I See Sharp

Roulette Implementation in C

2007-11-01T20:09:00.000+04:00

Here goes the main.c file:


/*
    Roulette program - by Rowan R. Jugernauth
    File description: Main application program with entry point
    Email: rowan.rishi@gmail.com
*/

#include <stdio.h>
#include <stdlib.h>
#include "Menus.h"

//starting player balance
const int startBalance = 5000;

//maximum bet
const int maxBet = 100;


//Main function of program
int main()
{
//number of players
int numPlayers;

//All players in the game
struct Player players[10];

//display the main menu
DisplayMenu();

//set the number of players
numPlayers = EnterPlayers();

//temporary variable
int i = 0;

//loop through the players and input their details
for (i = 0; i<=numPlayers-1; i++)
{
ClrScr();
printf("\n\n\n\tPlayer %d", i+1);
players[i] = InputPlayerDetails(startBalance);
}

//check if the game is over for all players
while(!IsGameOver(players, numPlayers))
{
//loop through the players and have them to play
for (i = 0; i<=numPlayers-1; i++)
{
        if (players[i].gameOver == 0)
        {
             StartGame(&players[i]);
        }
}

//generate random number and display score
Payout(&players, numPlayers);
}

//end program
Quit();
}


//starts the game for a certain player
void StartGame(struct Player * currentPlayer)
{
//reset all bets
ResetPlayerBets(currentPlayer, currentPlayer->balance);

//create a variable to define the user's choice    
int choice = -1;
int numBet = 0;
int amountBet = 0;
int totalBets = 0;

do
{
totalBets = CountPlayerBets(*currentPlayer);
PrintPlayerDetails(*currentPlayer);
choice = DisplayPlayerMenu();

switch(choice)
{
    case 0: //view board
        //view player bets
        DrawBoard(*currentPlayer);

        //wait for user to press key
        getch();

        //invalidate choice
        choice = -1;
        break;

    case 1: //bet on number
        //get which number the user just bet on
        numBet = BetOnNumber(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->numbers[numBet+1].bet);

        //increase bet on number
        currentPlayer->numbers[numBet+1].bet += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;
        break;

    case 2: //bet on red
        //display the board
        BetOnRed(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betRed);

        //increase bet on number
        currentPlayer->betRed += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;                        
        break;

    case 3: //bet on black
        //display the board
        BetOnBlack(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betBlack);

        //increase bet on number
        currentPlayer->betBlack += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;
        break;

    case 4: //bet on even
        //display the board
        BetOnEven(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betEven);

        //increase bet on number
        currentPlayer->betEven += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;    
        break;

    case 5: //bet on odd
        //display the board
        BetOnOdd(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betOdd);

        //increase bet on number
        currentPlayer->betOdd += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;
        break;

    case 6: //bet on low 18
        //display the board
        BetOnLo(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betLo);

        //increase bet on number
        currentPlayer->betLo += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;
        break;

    case 7: //bet on hi 18
        //display the board
        BetOnHi(*currentPlayer);

        //get the amount the user is betting
        amountBet = GetBetAmount(*currentPlayer, maxBet, currentPlayer->betHi);

        //increase bet on number
        currentPlayer->betHi += amountBet;

        //increase bet on number
        currentPlayer->balance -= amountBet;

        //invalidate choice
        choice = -1;
        break;

    case 8: //reset bets
        //reset the player's bets
        ResetPlayerBets(currentPlayer, currentPlayer->balance + CountPlayerBets(*currentPlayer));

        //invalidate choice
        choice = -1;
        break;

    case 9: //skip turn
        break;

    case 10: //call exit to terminate the program
        Quit();
        break;
}

} while ((choice < 1) || (choice > 10));
}

//Generate the winning number and display the earnings
void Payout(struct Player (*allPlayers)[10], int numPlayers)
{
//set winning number
int winningNum = Rand();

//Display winning information for the number
DisplayWinningInfo(winningNum);

//temporary integer
int i = 0;

//initialize a blank array for each player's earnings
int earnings[10] = {0,0,0,0,0,0,0,0,0,0};


//loop through the players and calculate their earnings
for (i=0; i<=numPlayers-1; i++)
{
if (IsNumberRed(winningNum))
{
    earnings[i] += (*allPlayers)[i].betRed * 2;
}

if (IsNumberBlack(winningNum))
{
    earnings[i] += (*allPlayers)[i].betBlack * 2;
}

if (IsNumberEven(winningNum))
{
    earnings[i] += (*allPlayers)[i].betEven * 2;
}

if (IsNumberOdd(winningNum))
{
    earnings[i] += (*allPlayers)[i].betOdd * 2;
}

if (IsNumberHi(winningNum))
{
    earnings[i] += (*allPlayers)[i].betHi * 2;
}

if (IsNumberLo(winningNum))
{
    earnings[i] += (*allPlayers)[i].betLo * 2;
}

earnings[i] += (*allPlayers)[i].numbers[winningNum].bet * 36;
}

//display all the earnings
DisplayEarnings(*allPlayers, earnings, numPlayers);

//increment the player's earnings and set their game over status
PayEarnings(*allPlayers, earnings, numPlayers);
}

There goes the Menu.h file:


/*
    Roulette program - by Rowan R. Jugernauth
    File description: Header file which contains the menu and misc. printing functions
    Email: rowan.rishi@gmail.com
*/

#include <stdio.h>
#include "Misc.h"
#include "Structures.h"


//display the welcome menu
void DisplayMenu()
{
ClrScr();
SetRGB(3);
GotoXY(26,0);
printf("=== Rowan's Roulette 1.0 ===");
}


//requests the user for the number of players
int EnterPlayers()
{
int players = 0;

while ((players < 2) || (players > 9))
{
 SetRGB(6);
 GotoXY(12,10);
 printf("Please enter the number of players [between 2 and 9]: ");
 SetRGB(2);
 scanf("%d", &players);

 if ((players < 2) || (players > 9))
 {
      GotoXY(12,10);
      SetRGB(1);     
      printf("\t\t\t\t\t\t\t\t[wrong]"); //clear the line and write "wrong" at the end.
 }
}

return players;
}


//input details of each player
struct Player InputPlayerDetails(int startBalance)
{
//create a new player
struct Player newPlayer;

//set the new player's game over to false
newPlayer.gameOver = 0;

SetRGB(6);
printf("\n\tPlease enter the player's name: ");
SetRGB(2);
scanf("%s", &newPlayer.name);


ResetPlayerBets(&newPlayer, startBalance);

return newPlayer;
}


//Display the player's details
void PrintPlayerDetails(struct Player somePlayer)
{
//display the top menu
DisplayMenu();

//count the player's bet
int sumBets = CountPlayerBets(somePlayer);

SetRGB(0);
GotoXY(60,2);
printf("%s's turn", somePlayer.name);

SetRGB(6);
GotoXY(60,3);
printf("Balance:");

GotoXY(69,3);
SetRGB(2);
printf("%d", somePlayer.balance);

SetRGB(6);
GotoXY(60,4);
printf("Sum Bet:");

GotoXY(69,4);
SetRGB(2);
printf("%d", sumBets);
}


//Display the menu intended for the player
int DisplayPlayerMenu()
{
int choice = 0;

printf("\n\n\t\t0. View current bets");
printf("\n\t\t1. Bet on a number (straight)");
printf("\n\t\t2. Bet on Red");
printf("\n\t\t3. Bet on Black");
printf("\n\t\t4. Bet on Even");
printf("\n\t\t5. Bet on Odd");
printf("\n\t\t6. Bet on Low-18");
printf("\n\t\t7. Bet on High-18");
printf("\n\t\t8. Clear all bets");
printf("\n\t\t9. Next player");
printf("\n\t\t10. Exit");

SetRGB(6);
printf("\n\n\tPlease enter a choice [0-10]: ");
SetRGB(2);
scanf("%d", &choice);
return choice;
}


//Asks the user to input a number to bet on
int BetOnNumber(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);
GotoXY(60,1);
SetRGB(3);
printf("Betting on a number");

int choice = -1;

do
{
 SetRGB(2);
 GotoXY(10, 22);
 SetRGB(6);
 printf("Please enter a number between 0 and 36. Enter -1 for 00: ");
 SetRGB(2);
 scanf("%d", &choice);

 if ((choice < -1 ) || (choice > 36))
 {
     SetRGB(1);
     GotoXY(10,22);
     printf("\t\t\t\t\t\t\t\t[wrong]"); //clear the line and write "wrong" at the end
 }

} while((choice < -1 ) || (choice > 36));

return choice;
}


//User is betting on red
void BetOnRed(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on red");
}

//User is betting on red
void BetOnBlack(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on black");
}

//User is betting on red
void BetOnEven(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on even");
}

//User is betting on red
void BetOnOdd(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on odd");
}

//User is betting on red
void BetOnLo(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on low-18");
}

//User is betting on red
void BetOnHi(struct Player currentPlayer)
{
//draw the board
DrawBoard(currentPlayer);

GotoXY(60,1);
SetRGB(3);
printf("Betting on high-18");
}

//Asks the user to input a bet amount
int GetBetAmount(struct Player currentPlayer, int maxBet, int currentBet)
{
int balance = currentPlayer.balance;
int betAmount = -1;

do
{
 SetRGB(0);
 GotoXY(10, 22);
 printf("\t\t\t\t\t\t\t\t"); //clear the line
 GotoXY(10, 22);
 printf("Amount already placed: %d", currentBet);
 SetRGB(2);
 GotoXY(10, 23);
 printf("\t\t\t\t\t\t\t\t"); //clear the line
 GotoXY(10, 23);
 SetRGB(6);
 printf("Please enter a bet amount between 0 and %d: ", maxBet);
 SetRGB(2);
 scanf("%d", &betAmount);

 if (betAmount > balance || betAmount > maxBet || (betAmount+currentBet > maxBet))
 {
     if ((betAmount+currentBet) > maxBet)
     {
         GotoXY(10, 24);
         printf("\t\t\t\t\t\t\t\t");
         GotoXY(10, 24);
         SetRGB(1);
         printf("This amount unfortunately exceeds the maximum bet.");
     }
     else
     if (betAmount > balance)
     {
         GotoXY(10, 24);
         printf("\t\t\t\t\t\t\t\t"); //clear the line
         GotoXY(10, 24);
         SetRGB(1);
         printf("This amount unfortunately exceeds your balance.");
     }
     getch();
 }     

} while ((betAmount < 0) || (betAmount > balance) || (betAmount+currentBet > maxBet));

return betAmount;
}

//Draw the board and display all of a player's bets
void DrawBoard(struct Player currentPlayer)
{
ClrScr();
int curX = 10;
int curY = 5;
int i = 2;

GotoXY(20, 2);
SetRGB(2);
printf("00");

GotoXY(30, 2);
printf("0");

SetRGB(0);
GotoXY(20, 3);
if (currentPlayer.numbers[0].bet > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
printf("$%d", currentPlayer.numbers[0].bet);

GotoXY(30, 3);
if (currentPlayer.numbers[1].bet > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
printf("$%d", currentPlayer.numbers[1].bet);

while (i <= 37)
{
 GotoXY(curX, curY);
 SetRGB(2);
 printf("%d",currentPlayer.numbers[i].value-1);
 if (currentPlayer.numbers[i].color == 'r')
 {
      SetRGB(1);
      printf("[R]");
 }
 //else
 //{
 //    SetRGB(5);
 //    printf("[B]");
 //}    

 if (currentPlayer.numbers[i].bet > 0)
 {
      SetRGB(9);
 }
 else
 {
      SetRGB(0);
 }

 GotoXY(curX, curY+1);
 printf("$%d",currentPlayer.numbers[i].bet);

 if (curX < 50)
 {
     curX += 10;
 }
 else
 {
     curX = 10;
     curY += 2;
 }

 i++;
}

SetRGB(2);
GotoXY(60, 5);
printf("HI Bets: ");

if (currentPlayer.betHi > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}

GotoXY(75, 5);
printf("%d", currentPlayer.betHi);

SetRGB(2);
GotoXY(60, 6);
printf("LO Bets: ");
if (currentPlayer.betLo > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
GotoXY(75, 6);
printf("%d", currentPlayer.betLo);


SetRGB(2);
GotoXY(60, 7);
printf("RED Bets: ");
if (currentPlayer.betRed > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
GotoXY(75, 7);
printf("%d", currentPlayer.betRed);

SetRGB(2);
GotoXY(60, 8);
printf("BLACK Bets: ");
if (currentPlayer.betBlack > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
GotoXY(75, 8);
printf("%d", currentPlayer.betBlack);


SetRGB(2);
GotoXY(60, 9);
printf("EVEN Bets: ");
if (currentPlayer.betEven > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
GotoXY(75, 9);
printf("%d", currentPlayer.betEven);

SetRGB(2);
GotoXY(60, 10);
printf("ODD Bets: ");
if (currentPlayer.betOdd > 0)
{
  SetRGB(9);
}
else
{
  SetRGB(0);
}
GotoXY(75, 10);
printf("%d", currentPlayer.betOdd);

}

//displays information about winning number
void DisplayWinningInfo(int winningNumber)
{
winningNumber -= 1;

ClrScr();
GotoXY(22,8);
SetRGB(5);
printf("And the winning number is... ");
SetRGB(2);

if (winningNumber == -1)
{
 printf("00!");
}
else
{
 printf("%d!", winningNumber);
}

GotoXY(20,10);
SetRGB(0);

if (IsNumberRed(winningNumber))
{
 printf("\n\t\tWinning number is Red!");
}

if (IsNumberBlack(winningNumber))
{
 printf("\n\t\tWinning number is Black!");
}

if (IsNumberEven(winningNumber))
{
 printf("\n\t\tWinning number is Even!");
}

if (IsNumberOdd(winningNumber))
{
 printf("\n\t\tWinning number is Odd!");
}

if (IsNumberHi(winningNumber))
{
 printf("\n\t\tWinning number is Hi!");
}

if (IsNumberLo(winningNumber))
{
 printf("\n\t\tWinning number is Lo!");
}

getch();
}

//Display each player's earnings
void DisplayEarnings(struct Player (*allPlayers)[10], int earnings[10], int numPlayers)
{
ClrScr();
int i = 0;

GotoXY(33,2);
printf("Player Scores");

SetRGB(5);
GotoXY(10,6);
printf("Player Name");
GotoXY(30,6);
printf("Old Balance");
GotoXY(45,6);
printf("Earnings");
GotoXY(60,6);
printf("New Balance");

int curY = 7;

SetRGB(5);
for (i = 0; i<=numPlayers-1; i++)
{
 SetRGB(0);

 GotoXY(10, curY);
 printf("%s", (*allPlayers)[i].name);

 SetRGB(0);

 GotoXY(30, curY);
 printf("%d", (*allPlayers)[i].balance);

 SetRGB(0);

 GotoXY(45, curY);
 printf("%d", earnings[i]);

 SetRGB(2);

 GotoXY(60, curY);
 printf("%d", earnings[i]+(*allPlayers)[i].balance);

 if ((*allPlayers)[i].balance + earnings[i] <= 0)
 {
      SetRGB(1);
      GotoXY(70, curY);
      printf("GAME OVER");
 }

 curY++;

}

getch();
}

This is the Misc.h file:


/*
    File description: Miscelleaneous functions
    Most functions are foreign implementations of useful functions
    Email: rowan.rishi@gmail.com
*/

#include <stdlib.h>
#include <windows.h>

//Clear the screen
void ClrScr()
{
system("CLS");
}

//THIS IS NOT CODE FROM ME. I COPIED THAT FROM THE NET
//go to specific coordinates on the screen 
void GotoXY(int x, int y)
{
static HANDLE hStdout = NULL;
COORD coord;

coord.X = x;
coord.Y = y;

if(!hStdout)
{
hStdout = GetStdHandle(STD_OUTPUT_HANDLE);
}

SetConsoleCursorPosition(hStdout,coord);
}

//THIS IS NOT CODE FROM ME. I COPIED THAT FROM THE NET
// Set text and background colors.
void SetRGB(int color)
{
switch (color)
{
case 0:    // White on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
 break;
case 1:    // Red on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_RED);
 break;
case 2:    // Green on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_GREEN);
 break;
case 3:    // Yellow on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_RED | FOREGROUND_GREEN);
 break;
case 4:    // Blue on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_BLUE);
 break;
case 5:    // Magenta on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_RED | FOREGROUND_BLUE);
 break;
case 6:    // Cyan on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_GREEN | FOREGROUND_BLUE);
 break;
case 7:    // Black on Gray
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     BACKGROUND_INTENSITY);
 break;
case 8:    // Black on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE);
 break;
case 9:    // Red on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_RED);
 break;
case 10: // Green on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_GREEN);
 break;
case 11: // Yellow on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_RED | FOREGROUND_GREEN);
 break;
case 12: // Blue on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_BLUE);
 break;
case 13: // Magenta on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_RED | FOREGROUND_BLUE);
 break;
case 14: // Cyan on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_GREEN | FOREGROUND_BLUE);
 break;
case 15: // White on White
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),BACKGROUND_INTENSITY |
     FOREGROUND_INTENSITY | BACKGROUND_RED | BACKGROUND_GREEN | BACKGROUND_BLUE |
     FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
 break;
default : // White on Black
 SetConsoleTextAttribute(GetStdHandle(STD_OUTPUT_HANDLE),FOREGROUND_INTENSITY |
     FOREGROUND_RED | FOREGROUND_GREEN | FOREGROUND_BLUE);
 break;
}
}

//generate a random number between 0 and 37
int Rand()
{
return ( (rand() % (38)));
//return 1;
}

//method to quit program
void Quit()
{
ClrScr();
SetRGB(2);
GotoXY(12, 10);
printf("By Rowan R. Jugernauth. Email: ");
SetRGB(0);
printf("rowan.rishi@gmail.com");
getch();
exit(0);
}

And finally, the structures.h file:


/*
    Roulette program - by Rowan R. Jugernauth
    File description: Contains structures and codes to deal with those structures
    Email: rowan.rishi@gmail.com
*/


//Defining a casino number
struct Number
{
//value of number
int value;

//bet value
int bet;

//red, black or green
char color;
};


//Defining a casino player
struct Player
{
//player's name
char name[32];

//player's balance
int balance;

//player's game status
int gameOver;

//All numbers in the game
struct Number numbers[38];

//amount bet on hi
int betHi;

//amount bet on lo
int betLo;

//amount bet on red
int betRed;

//amount bet on black
int betBlack;

//amount bet on even
int betEven;

//amount bet on odd
int betOdd;

};


//initialize variables
void InitNumbers(struct Player * somePlayer)
{
//temporary counter;
int counter;

//set the first number to -1. This actually represents 00
somePlayer->numbers[0].value = -1;
somePlayer->numbers[0].color = 'g';
somePlayer->numbers[0].bet = 0;

//loop through the numbers and reset their bets
for (counter = 1; counter<=37; counter++)
{
 //numbers[counter].bet = 250;
 somePlayer->numbers[counter].value = counter;
 somePlayer->numbers[counter].bet = 0;
}

//set the color for each roulette color
somePlayer->numbers[0].color = 'g';
somePlayer->numbers[1].color = 'g';
somePlayer->numbers[2].color = 'r';
somePlayer->numbers[3].color = 'r';
somePlayer->numbers[4].color = 'r';
somePlayer->numbers[5].color = 'b';
somePlayer->numbers[6].color = 'r';
somePlayer->numbers[7].color = 'b';
somePlayer->numbers[8].color = 'r';
somePlayer->numbers[9].color = 'b';
somePlayer->numbers[10].color = 'r';
somePlayer->numbers[11].color = 'b';
somePlayer->numbers[12].color = 'b';
somePlayer->numbers[13].color = 'r';
somePlayer->numbers[14].color = 'b';
somePlayer->numbers[15].color = 'r';
somePlayer->numbers[16].color = 'b';
somePlayer->numbers[17].color = 'r';
somePlayer->numbers[18].color = 'b';
somePlayer->numbers[19].color = 'r';
somePlayer->numbers[20].color = 'r';
somePlayer->numbers[21].color = 'b';
somePlayer->numbers[22].color = 'r';
somePlayer->numbers[23].color = 'b';
somePlayer->numbers[24].color = 'r';
somePlayer->numbers[25].color = 'b';
somePlayer->numbers[26].color = 'r';
somePlayer->numbers[27].color = 'b';
somePlayer->numbers[28].color = 'r';
somePlayer->numbers[29].color = 'b';
somePlayer->numbers[30].color = 'b';
somePlayer->numbers[31].color = 'r';
somePlayer->numbers[32].color = 'b';
somePlayer->numbers[33].color = 'r';
somePlayer->numbers[34].color = 'b';
somePlayer->numbers[35].color = 'r';
somePlayer->numbers[36].color = 'b';
somePlayer->numbers[37].color = 'r';
}


//reset all bets
void ResetPlayerBets(struct Player *newPlayer, int startBalance)
{
//initialize the player's start balance
newPlayer->balance = startBalance;
InitNumbers(newPlayer);
newPlayer->betBlack = 0;
newPlayer->betRed = 0;
newPlayer->betEven = 0;
newPlayer->betHi = 0;
newPlayer->betLo = 0;
newPlayer->betOdd = 0;
newPlayer->betEven = 0;
}


//counts all of a pleyer's bets
int CountPlayerBets(struct Player player)
{
int sum = 0;
int i = 0;

//sum bets for others
sum += player.betHi;
sum += player.betLo;
sum += player.betBlack;
sum += player.betEven;
sum += player.betOdd;

//sum bets for other numbers
for (i = 0; i<=37; i++)
{
 sum += player.numbers[i].bet;
}

//return sum
return sum;
}


//checks whether all players are ga
int IsGameOver(struct Player players[10], int numPlayers)
{
int overCount = 0;
int i = 0;

for (i = 0; i<=numPlayers-1; i++)
{
 if (players[i].gameOver == 1)
 {
     overCount++;
 }
}

return (overCount == numPlayers);
}


//sets all players to game-over
void SetAllGameOver(struct Player * players[10], int numPlayers)
{
int i= 0;

for (i=0; i<=numPlayers-1; i++)
{
 players[i]->gameOver = 1;
}
}


//method to check if a number is red
int IsNumberRed(int number)
{
struct Player tempPlayer;
InitNumbers(&tempPlayer);
if (tempPlayer.numbers[number+1].color == 'r')
{
 return 1;
}
else
{
 return 0;
}
}


//method to check if a number is black
int IsNumberBlack(int number)
{
struct Player tempPlayer;
InitNumbers(&tempPlayer);
if (tempPlayer.numbers[number+1].color == 'b')
{
 return 1;
}
else
{
 return 0;
}
} 


//method to check if a number is even
int IsNumberEven(int number)
{
//check if numbers aren't 00 and 0
if (number > 0)
{
 //check if even
 if ((number % 2) > 0)
 {
     return 0;
 }
 else
 {
     return 1;
 } 
}
else
{
 return 0;
} 
}


//method to check if a number is odd
int IsNumberOdd(int number)
{
//check if numbers aren't 00 and 0
if (number > 0)
{
 //check if odd
 if ((number % 2) > 0)
 {
     return 1;
 }
 else
 {
     return 0;
 } 
}
else
{
 return 0;
} 
}


//method to check if a number is hi
int IsNumberHi(int number)
{
//check if numbers aren't 00 and 0
if (number > 0)
{
 //check if odd
 if (number >= 18)
 {
     return 1;
 }
 else
 {
     return 0;
 } 
}
else
{
 return 0;
}
}    


//method to check if a number is lo
int IsNumberLo(int number)
{
//check if numbers aren't 00 and 0
if (number > 0)
{
 //check if odd
 if (number < 18)
 {
     return 1;
 }
 else
 {
     return 0;
 } 
}
else
{
 return 0;
}
}

//pay the earnings and set each player's game over status
void PayEarnings(struct Player (*allPlayers)[10], int earnings[10], int numPlayers)
{
int i = 0;

for (i = 0; i<=numPlayers-1; i++)
{
 //if the player isn't game over yet
 if ((*allPlayers)[i].gameOver == 0)
 {
     (*allPlayers)[i].balance += earnings[i];

     //set the player's game over status if balance zero or less
     if ((*allPlayers)[i].balance <= 0)
     {
         (*allPlayers)[i].gameOver = 1;
     }
 }
}
}

Please let me know if there are any bugs or corrections to be made!
Cheers,
Rowan

Connecting MySQL and C#

2006-09-26T03:20:00.000+04:00

I wrote an article on how you can connect MySQL to C# a while back. I thought it'd be interesting to give you guys a "better" article on how this can be done, with more theory and examples.

MySQL is quite cool if you don't have huge amounts of data to handle - and it's free. To better understand this tutorial, you'll need:

1. MySQL Server
2. MySQL Administrator
3. MySQL Connector .net

MySQL Server
MySQL Server is the real thing. It's the core of the database and is accessible after install through the command line. The MySQL server, by default, is a service running in the background. If you cannot connect to the MySQL server, check whether it's running in your services list.

MySQL Administrator
The MySQLAdministrator can be freely downloaded at the MySQL website. It helps you create and manage databases as well as tables with a graphical user interface. Yes. No console and commands bullshit - a few clicks and you'll be rolling with your own database and tables. If you're having problems to connect to the MySQL Administrator, note that:

The Server Host should be set to the machine-name or IP where your MySQL Server is located (if you installed it on your own pc, it's localhost).
The Username is root
The Password is the password you specified during install. Blank if you didn't specify any or wasn't even asked for one and...
The Port is 3306, unless you specified something else during install.

The MySQL Connector .Net
This tool is also freely available for downloading from the MySQL website. It's a DLL that you should add as reference in your C# project. The DLL is located under your %programfiles%\MySQL\MySQL Connector Net 1.0.4\bin\.NET 1.1\MySql.Data.dll, unless you specified something else during install.

Your First C# Program That Uses MySQL
Right. You've installed the MySQL server, the MySQL Administrator and the MySQL Connector. What you need to do is create a new console application, and add a reference to MySQL's connector (normally located under %programfiles%\MySQL\MySQL Connector Net 1.0.4\bin\.NET 1.1\MySql.Data.dll).

Opening and closing the connection is easy, now that you've added the reference:

using System;
using MySql.Data.MySqlClient;

namespace ConsoleApplication1
{
class ConnectToMySQL
{
    [STAThread]
    static void Main(string[] args)
    {
        //create a MySQL connection with a query string
        MySqlConnection connection = new MySqlConnection("server=localhost;database=cs;uid=root;password=abcdaaa");

        //open the connection
        connection.Open();

        //close the connection
        connection.Close();
    }
}
}

Note that the format of the SQL query string is as follows:

server=$servername$;database=$databasename$;uid=$username$;password=$password$;

Where $servername$ is the name of the machine where your MySQL Server is running (localhost if it's on your own machine) and $databasename$ the name of your database (or catalog, as some call it), $username$ a user which is allowed to access the database you selected and $password$ the password of the user. For the dickheads who are too lazy to write their own connection strings, here goes a method which should generate good connection strings for you:

       /// <summary>
     /// Generates a connection string for lazy bastards
     /// </summary>
     /// <param name="server">The name or IP of the machine where the MySQL server is running</param>
     /// <param name="databaseName">The name of the database (catalog)</param>
     /// <param name="user">The user id - root if there are no new users which have been created</param>
     /// <param name="pass">The user's password</param>
     /// <returns></returns>
     public static string CreateConnStr(string server, string databaseName, string user, string pass)
     {
         //build the connection string
         string connStr = "server=" + server + ";database=" + databaseName + ";uid=" +
             user + ";password=" + pass + ";";

         //return the connection string
         return connStr;
     }

This method generates a connection string that you can use in the MySQLConnection object constructor. The console application, with the new added method to generate the Connection String now looks like this:


using System;
using MySql.Data.MySqlClient;

namespace ConsoleApplication1
{
   class ConnectToMySQL
   {
       [STAThread]
       static void Main(string[] args)
       {
           //generate the connection string
           string connStr = CreateConnStr("localhost", "cs", "root", "abcdaa");
          
           //create a MySQL connection with a query string
           MySqlConnection connection = new MySqlConnection(connStr);

           //open the connection
           connection.Open();

           //close the connection
           connection.Close();
       }

       /// <summary>
       /// Generates a connection string for lazy bastards
       /// </summary>
       /// <param name="server">The name or IP of the machine where the MySQL server is running</param>
       /// <param name="databaseName">The name of the database (catalog)</param>
       /// <param name="user">The user id - root if there are no new users which have been created</param>
       /// <param name="pass">The user's password</param>
       /// <returns></returns>
       public static string CreateConnStr(string server, string databaseName, string user, string pass)
       {
           //build the connection string
           string connStr = "server=" + server + ";database=" + databaseName + ";uid=" +
               user + ";password=" + pass + ";";

           //return the connection string
           return connStr;
       }
   }
}

However, all we're doing is to connect and disconnect from the MySQL server without adding or taking out data. If you want to know more about how to do this, read this article.

Now, for those who want to deal with single inverted commas in MySQL and block SQL injection attacks, here are a few solutions for you:

1. Replace all single inverted commas by two single inverted commas.
2. Replace all single inverted commas by a slash and then the inverted comma.
3. Convert the inverted comma (and any other character that is not "normal") into its HTML-ASCII equivalent before adding it into the database.

Increase Array Bounds in C#

2006-09-26T03:06:00.000+04:00

It's been a long time since I posted anything useful on this blog. I recently looked up the list of things people were looking for before falling onto this blog.

Increase Array Bounds in C#
For those of you who are new to C#, let me quickly sum this up: don't use arrays unless you're absolutely and positively certain that the array you're using will never use more than the number of values you created it for. Use an array for the number of days. Use an array of 8 bits to hold a byte. Use an array of 12 for the number of months. Those are values that we're absolutely sure will never change.

If you ever need to increase the size of an array somewhere in your code - you had it wrong. Use the ArrayList from the System.Collection namespace, or List System.Collections.Generic if you're on .Net 2.0 to create and use dynamic arrays.

Here's some sample code for you to have fun with:


           //create an arraylist to hold some values
           ArrayList myList = new ArrayList();

           //add a few values to the arraylist
           myList.Add(10);
           myList.Add(11);
           myList.Add(8);

           //value to hold the sum of the values
           int sum = 0;

           //sum the values in the arraylist
           foreach (int i in myList)
           {
               sum += i;
           }

           //display the sum
           Console.WriteLine(sum.ToString());

How I Began Coding

2005-10-18T00:08:00.000+04:00

Here's the incredible story of how I began coding ~

I remember my dad coming home with this dark gray box that would flip open - a laptop. That was something quite expensive to have during that time. I was only 5 years old, and the year was 1990. He was working as a photograph-reporter for the Mauritian Sun newspaper, and the laptop belonged to his office. I don't remember much from the computer itself, but I do remember Shamush, and BASICA.

My dad taught me my first program.

Hello, What is your name? ROWAN
Hello ROWAN

Fascinating. The ability to make the computer do what I wanted it to do. A few months later, my dad brought home a few books on BASICA. I wasn't reading it - I could barely understand English. I was just copying the examples and executing them. I started by faithfully copying down the code and then ended up modifying almost every number I could find. Thousands became millions, hundreds became zeroes. I just loved it.

Windows 95 was out, and my cousin and myself were hooked up on F1GP on my uncle's PC. And on QBasic as well. My cousin Ashvin was two years older than I was, and he had learnt quite a few tricks in programming. I could write a few stuff in QBasic as well, but I couldn't go far without the QBasic Help. I was 10-11, and I started to learn about variables. I was awed to hear about the existence of Arrays, and I heard about compilation. Compiling - the ability to make your own executables. I never wrote any useful program during that time, but I learnt a few batch-file tricks from my cousin.

I eventually ended up with my own PC in 1998, and I was off writing useless programs in QBasic. I barely understood the concepts of programming, and I hadn't heard about algorithms yet.

I met Arvind during that time. We were in school together, and we became friends. He was the batch-file genius. He had devised countless ways to include programs in batch files and make everything work together. To bad ends. He was mostly up to replacing the good old win.com by funny programs.

For the last time in my programming marathon, my dad intervened. He had bought a PC-Format magazine, which contained the full version of Borland Delphi 1. I tried it out, and fell in love with it. The help was pretty bad, but I managed to get a few working examples here and there. I was now working with forms, without having the slightest idea of what an object was, nor about Windows API calls. And the best thing about it was that I could create my own executables! Perfect!

Pretty soon, Arvind got his own copy of Delphi and stopped trying to replace win.com with other things. We were off to write **real** programs.

I eventually ended up with a modem and 56k internet. That was where I started to learn about characters, boolean values, methods, and also loops.

I don't know what went through Arvind's head, but he signed me up for a programming competition. He told the teacher that I was "good". Nope, I wasn't good at all, and I still hadn't tried writing complicated algorithms. I spent some time learning the real pascal, but still failed miserably in the competition, while Arvind got himself a bronze medal.

The competition was organised by the DCDM business school, and they held a programming bootcamp for all the participants of their previous competition. That was where I got taught everything I missed in programming. The bootcamp was also the place where I met Dimple, who would become my good friend later on. She was the cutest thing I had ever seen at 16, and the gleaming gold medal she had previously won had left me speechless.

After the training camp, Arvind taught me about pointers. I couldn't really understand the purpose of it all, but I still managed to make my own linked list. After a few weeks of practise, I made my own binary tree without any help on Pascal. I was getting better at coding.

The competition was held again the next year and I came out sixth with a silver medal. The first four guys were going to be sent to the IOI which was being organised in Finland, and there was a training camp which was being organised for them at the DCDM Business school. I was one of the replacement team members, which allowed me to follow Vik Nuckchady and Sarita Hardin's programming lessons along with the other better guys.

The guy who came out first was barely as tall as myself, with his hair in all directions and a fucked up sense of humour. Dominique. That was where I met him, although we didn't really become friends at that time. Programming was becoming more and more part of my life with every passing day. I had learnt about API calls, performance and memory optimization and a whole host of programming tricks designed to mainly impress your friends.

The programming competition was held again the next year. I was 17, Arvind 19, and Dominique 18. The day before, Arvind had taught me about the 8-Queen problem, and surprisingly enough, it came out as the final question of the competition. I came out third, Dom first (as usual), and Arvind got himself a silver medal. We were trained and sent off to the IOI which was being held in South Korea.

I became friends with Dom in Korea. None of us earned anything at all, but we were still glad to have participated. I lent Dom one of my books on Delphi, and after a few months, he became the Delphi expert.

He introduced me to OOP, although I didn't really like the concept. Most of my programs were still straightforward - I would usually kick in everything in one object, never instantiating or destroying anything at all. I kept this style of coding until we found a job.

Dom called me up one day, saying that he got an interview for a job for the both of us. I was 18, and Dom 19. The interview went fine, and we were told that we would receive about 8 months of training before we began working on solid projects.

The guy who trained us was also our CTO - Cuan brown - or Q. Although I was barely awake in Q's classes, I must admit that he did raise me from the level of n00b to something of a programmer. Q's training wasn't focused only on programming; he was constantly kicking our asses to get us to write good professional code. I was still a Delphi coder during that time, but Cuan (through brutal and sadomaschistic means) made me like C#. This blog, my .NET projects, the programs that I wrote and that are currently running in background, my ASP and ASP.NET pages and even some of the porn I leeched all exist thanks to Q. He kicked my ass and made me work with ASP, forced me to work with CSS and helped me with most of my web-related work. Nowadays, most of the code that I write would bear this faint italicized trace: Q's shoe in my butt while he was exclaiming:

"Fucking Muppets Need Fucking Training"

Arrays in C# and C

2005-10-03T22:13:00.000+04:00

Arrays
[Static Arrays in C and C#]

I never pictured myself writing a tutorial on arrays but here we are - a tutorial on arrays. I'm basically writing this because we just did arrays at uni (C programming language, duh), and a few of my friends came sort of late (and some of them went to the outing) and couldn't understand fuck at all on what the whole deal was about with arrays.

Arrays. I read about arrays when I was 12. It was a Q-Basic tutorial. I still remember, it was saying something like "picture arrays like boxes" ... well anyway, never mind the way you're picturing arrays, let me just start with a small intro on data and arrays.

Please keep in mind that this is a C# blog; the C language and its construct is outside the scope of this blog. However, because I own and maintain this thing, I do pretty much whatever I want with it. You will notice that arrays in C and C# are somewhat similar. Actually, the concept of Arrays remains the same throughout all programming languages. Except ASM and VB. ASM coz you have to write your own shit and deal with it, and VB coz you prolly need to write a poem for the compiler to give you an array. No, well, it's the same in VB too :)

Intro

Useful programs need to be fed data to be processed. At some point or the other, it might happen that we need a large amount of the same type of data to hold stuff. Example, if you wanted to hold the salary of 10 employees - you could do something like:

C and C# Code


int Employee1;
int Employee2;
int Employee3;
int Employee4;
int Employee5;
int Employee6;
int Employee7;
int Employee8;
int Employee9;
int Employee10;

But that's not really neat-looking. I mean, what if you had 10,000 employees? Heh, that would sort of suck, wouldn't it? Arrays provide a simpler way of storing large amounts of data. You can declare, in one line:

C Code


int Employees[9];

C# Code


int[] Employees = new int[9];

Declaring an array of of length 9 (int[9] in C# and variableName[9] in C) would be the same as declaring 10 integer elements. Why does an array with accessor [9] have 10 elements? Simple - because an array's elements start with 0.

C and C# Code


Employees[0];    //Employee 1
Employees[1];    //Employee 2
Employees[2];    //Employee 3
Employees[3];    //Employee 4
Employees[4];    //Employee 5
Employees[5];    //Employee 6
Employees[6];    //Employee 7
Employees[7];    //Employee 8
Employees[8];    //Employee 9
Employees[9];    //Employee 10

Assigning Values To Arrays

Assigning a value to an array is pretty simple. We can do this:

C Code


int Employees[4];

Employees[0] = 2400;
Employees[1] = 2100;
Employees[2] = 3050;
Employees[3] = 2400;
Employees[4] = 3380;

C# Code


int[] Employees = new int[4];

Employees[0] = 2400;
Employees[1] = 2100;
Employees[2] = 3050;
Employees[3] = 2400;
Employees[4] = 3380;

There is, however, an easier way of assigning values in an array. Here goes the code:

C Code


int Employees[4] = {2400,2100,3050,2400,3380};

C# Code


 int[] Employees = {2400,2100,3050,2400,3380};

Arrays just make the world easier for us. However, behaviour of arrays on C and other programming languages are sort of different. While most modern languages have bounds checking for arrays, C doesn't. For those who have no clue what bounds checking is about - it's just checking whether someone is trying to access an array's elements outside of its specified bounds. You can access the 5th element in an array of 50 items, but you can't access the 1000th element in that same array. In C#, if you try such a thing, an exception will be thrown. In C, nothing will happen - your program will continue to execute, although you'll now have weird garbage data which was used. Example:

C Code


int Employees[4] = {2400,2100,3050,2400,3380};
printf("%d", Employees[50]); //Will Output Garbage Data

C# Code


int[] Employees = {2400,2100,3050,2400,3380};
Console.WriteLine(Employees[50].ToString()); //Will Raise an Exception

While the above C example will run without bitchin' you, C# will give you a System.IndexOutOfRangeException - which is a kind way of saying you fucked up on the array's bounds. C# does check if your code is straying outside the bouds of an array, while C doesn't. It just applies a formula which calculates the memory location of the designated element in the array, reads the memory location, and returns you the result. Voila. You'll have to deal with it by writing proper code, that's all. While dealing with arrays, if you ever end up with garbage data (e.g. an element of array of int returning you -244324 instead of a plain 0), you'll know that you fucked up with the bounds somewhere in your code.

Here's the deal: You can write programs fast in C#, but your programs will consume more processing power, and might eat up more memory space. In C, writing programs is like anal sex, but the programs will run like Beep-Beep with its ass on fire.

Anyway, let's get on with arrays. You can create an array of any type. An array of characters, an array of integers, an array of float - whatever you can think of. The arrays we're discussing here are called "static" arrays. Static arrays have a fixed size (and therefore number of elements). You can't increase the size of the array, nor decrease it. There are several other kinds of arrays in C#, namely dynamic arrays (ArrayLists - hehe) and jagged arrays, but those are outside of the scope of this tutorial.

Multi Dimensional Arrays

What we're going to do now is look at multidimensional arrays. Never mind about the name - Multi Dimensional arrays are just arrays made up of arrays. Let's imagine for a moment that there is a shop which sells Shoes, Hats, and Gloves. We want to represent the number of items sold per day in a grid, as follows:


        Mon Tue Wed Thu Fri Sat
Shoes     0   0   1   0   0   2 
Hats      2   1   2   2   1   3
Gloves    0   0   0   0   2   1

To store that data, we could:

C Code


int Shoes[5];
int Hats[5];
int Gloves[5];

C# Code


int[] Shoes = new int[5];
int[] Hats = new int[5];
int[] Gloves = new int[5];

or Alternatively:

C Code


int Mon[2];
int Tue[2];
int Wed[2];
int Thu[2];
int Fri[2];
int Sat[2];

C# Code


int[] Mon = new int[2];
int[] Tue = new int[2];
int[] Wed = new int[2];
int[] Thu = new int[2];
int[] Fri = new int[2];
int[] Sat = new int[2];

Shoes[0] would represent the number of shoes sold on Monday, Shoes[1] the number of shoes sold on Tuesday, Gloves[5] the number of gloves sold on Saturday; while on the alternative example, Mon[0] would represent the number of Shoes sold on monday, Mon[1] the number of Hats sold on Monday, Thu[2] the number of Gloves sold on Thursday, and so on. That's not a bad way of doing things. Nowever, if the shop was selling more than 500 items, it would get a little bit difficult to make this work with our current method. Not that it's impossible - but it's not the right way of doing things. This is where multidimensional arrays come into play.

C Code


int ItemsSold[2][5];

C# Code


int[][] ItemsSold = new int[2][5];

The declaration ItemsSold[2][5] in C and int[2][5] in C# is the one of a multidimensional array. Those kinds of arrays allow the user to create arrays of 2, 3, 4 or even N dimensions, according to the needs of the program. Here's a description of how the data is going to be stored in my array:


ItemsSold[0][0];  // Shoes sold on Mon
ItemsSold[0][1];  // Shoes sold on Tue
ItemsSold[0][2];  // Shoes sold on Wed
ItemsSold[0][3];  // Shoes sold on Thu
ItemsSold[0][4];  // Shoes sold on Fri
ItemsSold[0][5];  // Shoes sold on Sat

ItemsSold[1][0];  // Hats sold on Mon
ItemsSold[1][1];  // Hats sold on Tue
ItemsSold[1][2];  // Hats sold on Wed
ItemsSold[1][3];  // Hats sold on Thu
ItemsSold[1][4];  // Hats sold on Fri
ItemsSold[1][5];  // Hats sold on Sat

ItemsSold[2][0];  // Gloves sold on Mon
ItemsSold[2][1];  // Gloves sold on Tue
ItemsSold[2][2];  // Gloves sold on Wed
ItemsSold[2][3];  // Gloves sold on Thu
ItemsSold[2][4];  // Gloves sold on Fri
ItemsSold[2][5];  // Gloves sold on Sat

Well, yes, we could have reversed it all. We could have made a 2-dimensional array which has its first dimension representing the day, and the second dimension representing the item. The code would look like this:

C Code


int ItemsSold[5][2];

C# Code


int[][] ItemsSold = new int[5][2];

The arrys would represent:


ItemsSold[0][0];  // Monday's sales of Shoes
ItemsSold[0][1];  // Monday's sales of Hats
ItemsSold[0][2];  // Monday's sales of Gloves

ItemsSold[1][0];  // Tuesday's sales of Shoes
ItemsSold[1][1];  // Tuesday's sales of Hats
ItemsSold[1][2];  // Tuesday's sales of Gloves

ItemsSold[2][0];  // Wednesday's sales of Shoes
ItemsSold[2][1];  // Wednesday's sales of Hats
ItemsSold[2][2];  // Wednesday's sales of Gloves

ItemsSold[3][0];  // Thursday's sales of Shoes
ItemsSold[3][1];  // Thursday's sales of Hats
ItemsSold[3][2];  // Thursday's sales of Gloves

ItemsSold[4][0];  // Friday's sales of Shoes
ItemsSold[4][1];  // Friday's sales of Hats
ItemsSold[4][2];  // Friday's sales of Gloves

ItemsSold[5][0];  // Saturday's sales of Shoes
ItemsSold[5][1];  // Saturday's sales of Hats
ItemsSold[5][2];  // Saturday's sales of Gloves

Assignment of dimensions is up to you - whether you want to put the days in the first dimension or in the second all depends on you and what you want to code.

Finally...

Finally, when should we use static arrays, and when should we use dynamic arrays? Static arrays should be used when you're ABSOLUTELY certain that the size of the array will never exceed a certain limit. Example - number of days in a week, number of days in a month (even if it's sometimes 28,29,30 or 31, declaring an array with 31 elements is enough. We might be wasting 4-16 bytes, but it's still ok).

However, we SHOULD use dynamic arrays when we're not certain about the number of elements that is going to fit into the array. E.g. Number of employees, number of files in a directory, number of items being sold by a shop(yes, that can vary).

Dynamic arrays contain additional code to make the whole thing work - which makes it slower. Static arrays are pretty straightforward when it comes to execution - not much code, executes fast.

I hope you enjoyed reading the tutorial :)
I would like to express my warmest thanks to:

My 1.5 Gb of Ram, for helping me, all the time
My new screen, for not being a blurry dick
Michael Jackson, for not reading this tutorial
The internet, and TCP/IP for making this possible
Notepad, a friend of mine.
Bill Gates, for nothing

I'm dedicating this tutorial to my uni friends who are completely clueless about arrays; and to my one and only frequent reader (yeah, I've got only one fucking "frequent" reader. Damn. Thought I was popular.) Ahad. Yo dude! What's up? :P

Popularity Checking Tool - And Random Thoughts

2005-09-18T20:53:00.000+04:00

Find out if you're popular or not.
[Yay, my popularity is 0.0000000000000000000000000000000000001]

I was a little bit busy. I had homework to do, I had an assignment to complete and on top of that, I'm working on a freelance job, and I have 2 personal projects running. Which leaves me with plenty of free time to think about nonesense. I was wondering whether there's a way of measuring one's popularity. Of course, if you want to measure something, you need to have something else against which to compare the value.

I devised an ingenious (and perfectly flawed) means of finding out a person's popularity, which I decided to baptize (2 minutes ago) as the "Rowan-Dynamic-Popularity-Counter". Rowan, because it's my name. Dynamic, because it sounds cool, and popularity counter, because after performing the various hyper-complex mathematical calculations involving addition and division of whole numbers, you're left with a floating point value which represents an invividual's popularity, compared to another one.

Comparing your popularity won't work, if you're a "normal" individual. This technique of finding popularity is solely based on the number of web pages that contains your name. You need to be some kind of actor/actress, or singer or somebody who yields more than 1000 page results on search engines with your name being the exact keyword. Although it doesn't really represent real-world statistics, it does mirror popularity to a certain extent.

Well, yes. My RDPC (Rowan Dynamic Popularity Counter (TM)) algorithm involves the use of search engines to count the number of results returned with exact matching keywords. Of course, because nothing is absolute in this universe, you have to compare the total number of results with a known celebrity's return results.

The use of multiple search engines will theoretically yield better results, if we consider that different search engines cover different parts of the internet (although this is not totally true).

I needed a lab rat. I found the name "Jaime Ray Newman" on IMDB. Turns out she stars in 2 episodes of SG-Atlantis. Maybe I should download those sometime soon... I tested her popularity against Nicole Kidman's:

[J] represents Jaime, [K] represents Nicole Kidman

google
[J] 44,400
[K] 5,790,000
-> 0.77%

msn
[J] 1,163
[K] 802,235
-> 0.14%

yahoo
[J] 2,560
[K] 10,300,000
-> 0.02%

all the web
[J] 1,150
[K] 4,690,000
-> 0.02%

Average: 0.24%

Jamie Ray Newman is therefore currently at 0.24% (18 Sep 05) of Nicole Kidman's popularity. Yep... Now time for automation. How about putting all of this into a little C# program that'll do the job for us, eh? Hehe... It'll be a totally useless program, but there's worse. Look what I found (quoted from http://www.tifareth.com/tpsy.html):

Tele Hypnosis Pro is a esoteric program that uses the occult power of your computer to influence people remotely; the program takes its root in the ancient qabalistic magick and the modern psychotronics, giving you an unvaluable tool to influence people remotely. The effect of the program is natural and progressive; that means that the effects are not sudden, so the person will never know that has been submitted to remote mind control; the effects are progressive, so for example, if you use TELE HYPNOSIS PRO to seduce remotely a woman that previously ignored you, the effects will be progressive, she will start to feel some attraction for you, that with the continue usage of the program, will become love, and finally, deep love; the effect is so natural that she will never suspect she was submitted to remote mind control; she will always think that she fell in love for you in a natural way.

I always thought I was a bit crazy. I really feel normal now. And I'm proud I can write fairly good English.

Coming up next week: A full tutorial on how to use the System.Occult namespace, and make use of the System.Occult.MindControl class. If you don't have the Occult namespace on your GAC, download the ODK (Occult Development Kit) from Microsoft. It's free.

MySQL with C#

2005-09-07T19:48:00.000+04:00

A quick intro
Is MySQL really mine?

Hello guys. I'm back from uni, and in full health. I've got so many new things to tell you, so many new things to teach you... hehe! :)

MySql is one of the most popular (and free) database management software around. You can have a look and freely download MySQL at www.mysql.com - make sure to download the .Net connector and also the MySQL administrator if you can. It's pretty useful if you don't know much of MySQL.

Now, let's get started. After downloading MySQL, MySQL's Administrator and MySQL Connector, make sure you're not a silly dick with a condom stuck up in your ass. Already checked? Okay, we're set to go.

We'll open up MySQL Administrator. The MySQL Administrator provides a nice user interface for people like me and you (if you're reading this, then I guess you don't know much about SQL) who aren't quite fluent in SQL. Well, I wasn't a few months ago, but now I'm some kind of advanced noob. Anyways, open up MySQL Administrator. You'll see something like this:

I remember being stuck on this fucking screen for quite some time the first time I opened up MySQL. Well duh, of course, the server host is localhost, and the username is "root" (and not "sa"). The password's the password that you typed in during installation. Don't change the port unless you specified something else during install. Click on OK. You should now be into MySQL Administrator.

At the top left, you'll see a menu with pretty icons on it. There's mainly "Server Information" which gives you information about your SQL server, Service Control - which allows you to start / stop / restart the MySQL service on your machine, Startup Variables - some useful variables and paths for MySQL, User Administration - where you can create / manage / delete / update users, etc... I'm not going to explain in detail what each of the menu items do, they're pretty much straightforward I think :)

Let's get straight to the point. What interests us for the moment is the Catalogs menu item, found at the bottom of the top-left menu. Click on the catalog, and create a new catalog by right-clicking on some empty space on the list box right beneath the top-right menu. Choose "Create New Schema". By default, mysql already has a few schema's created, but never mind about them. Create a new one, called CS. CS, of course, doesn't stand for Counter-Strike (as many dick-heads might have thought), but rather for C-Sharp. This is going to be our test catalog.

Right, after creating that schema, we'll need to create a new table for it. Right click on the big space on the right of the menu's (where obviously the tables should be, but aren't) and click on Create Table. Well, heh, you can also click on the little "Create Table" button, but that's all up to you.

Create a table named users. Make sure the table is of type "MyISAM" and not "InnoDB". We don't need to use transactions here :) Here are screenshots of my users table:.

Here are the types I used. Make sure usr_Name (the username) and usr_Pass are maked as "Binary". Else, the username and passwords wouldn't be case-sensitive at all.

We don't need no transactions! Use MyISAM storage engine.

Right. Now that our tables are set up, we can open up our C# editor. Create a new console application. Add a reference to the MySQL .net Connector (which I'm sure you already downloaded and installed from this location). The MySQL connector for the .Net framework 1.0, after installation, can normally be found at [MySQLInstallPath]\MySQL Connector Net 1.0.4\bin\.NET 1.0

Here's the wrapper that I wrote for this example. It's pretty straightforward. There's a class called "DbWrapper" which does all the database work for us. The DbWrapper has methods to add a user, verify whether a username exists or not, and validate a username and password.


using System;
using MySql.Data.MySqlClient;

namespace CSConnector
{
    /// <summary>
    /// Wraps calls to the users database
    /// </summary>
    public class DbWrapper
    {
        private MySqlConnection sqlConn;
        private string connStr;
        private bool isConnected;

        /// <summary>
        /// Creates a new database wrapper object that wraps around
        /// the users table.
        /// </summary>
        /// <param name="svr">The name of the server</param>
        /// <param name="db">The database catalog to use</param>
        /// <param name="user">The user name</param>
        /// <param name="pass">The user password</param>
        public DbWrapper(string svr, string db, string user, string pass)
        {
            this.connStr = "Server="+svr+";Database="+db+";Uid="+user+";Pwd="+pass+";";
            
            try
            {
                sqlConn = new MySqlConnection(this.connStr);
            }
            catch(Exception excp)
            {
                Exception myExcp = new Exception("Error connecting you to " +
                    "the my sql server. Internal error message: " + excp.Message, excp);
                throw myExcp;
            }

            this.isConnected = false;
        }

        /// <summary>
        /// Creates a new database wrapper object that wraps around
        /// the users table.
        /// </summary>
        /// <param name="connStr">A connection string to provide to connect
        /// to the database</param>
        public DbWrapper(string connStr)
        {
            this.connStr = connStr;

            try
            {
                sqlConn = new MySqlConnection(this.connStr);
            }
            catch(Exception excp)
            {
                Exception myExcp = new Exception("Error connecting you to " +
                    "the my sql server. Error: " + excp.Message, excp);
                
                throw myExcp;
            }

            this.isConnected = false;
        }

        /// <summary>
        /// Opens the connection to the SQL database.
        /// </summary>
        public void Connect()
        {
            bool success = true;

            if (this.isConnected == false)
            {
                try
                {
                    this.sqlConn.Open();
                }
                catch(Exception excp)
                {
                    this.isConnected = false;
                    success = false;
                    Exception myException = new Exception("Error opening connection" +
                        " to the sql server. Error: " + excp.Message, excp);
                    
                    throw myException;
                }

                if (success)
                {
                    this.isConnected = true;
                }
            }
        }
        
        /// <summary>
        /// Closes the connection to the sql connection.
        /// </summary>
        public void Disconnect()
        {
            if (this.isConnected)
            {
                this.sqlConn.Close();
            }
        }

        /// <summary>
        /// Gets the current state (boolean) of the connection.
        /// True for open, false for closed.
        /// </summary>
        public bool IsConnected
        {
            get
            {
                return this.isConnected;
            }
        }

        /// <summary>
        /// Adds a user into the database
        /// </summary>
        /// <param name="username">The user login</param>
        /// <param name="password">The user password</param>
        public void AddUser(string username, string password)
        {
            string Query = "INSERT INTO users(usr_name, usr_pass) values" +
                "('"+username+"','"+password+"')";

            MySqlCommand addUser = new MySqlCommand(Query, this.sqlConn);

            try
            {
                addUser.ExecuteNonQuery();
            }
            catch(Exception excp)
            {
                Exception myExcp = new Exception("Could not add user. Error: " +
                    excp.Message, excp);
                throw(myExcp);
            }
        }

        /// <summary>
        /// Verifies whether a user with the supplied user
        /// credentials exists in the database or not. User
        /// credentials are case-sensitive.
        /// </summary>
        /// <param name="username">The user login</param>
        /// <param name="password">The user password</param>
        /// <returns>A boolean value. True if the user exists
        /// in the database, false if the user does not exist
        /// in the database.</returns>
        public bool VerifyUser(string username, string password)
        {
            int returnValue = 0;

            string Query = "SELECT COUNT(*) FROM users where (usr_Name=" +
                "'"+username+"' and usr_Pass='"+password+"') LIMIT 1";

            MySqlCommand verifyUser = new MySqlCommand(Query, this.sqlConn);

            try
            {
                verifyUser.ExecuteNonQuery();

                MySqlDataReader myReader = verifyUser.ExecuteReader();

                while(myReader.Read() != false)
                {
                    returnValue = myReader.GetInt32(0);
                }

                myReader.Close();
            }
            catch(Exception excp)
            {
                Exception myExcp = new Exception("Could not verify user. Error: " +
                    excp.Message, excp);
                throw(myExcp);
            }

            if (returnValue == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }

        /// <summary>
        /// Checks whether a supplied user name exists or not
        /// </summary>
        /// <param name="username">The user name</param>
        /// <returns>True if the username is already in the table,
        /// false if the username is not in the table</returns>
        public bool UserExists(string username)
        {
            int returnValue = 0;

            string Query = "SELECT COUNT(*) FROM users where (usr_Name=" +
                "'"+username+"') LIMIT 1";

            MySqlCommand verifyUser = new MySqlCommand(Query, this.sqlConn);

            try
            {
                verifyUser.ExecuteNonQuery();

                MySqlDataReader myReader = verifyUser.ExecuteReader();

                while(myReader.Read() != false)
                {
                    returnValue = myReader.GetInt32(0);
                }

                myReader.Close();
            }
            catch(Exception excp)
            {
                Exception myExcp = new Exception("Could not verify user. Error: " +
                    excp.Message, excp);
                throw(myExcp);
            }

            if (returnValue == 0)
            {
                return false;
            }
            else
            {
                return true;
            }
        }


    }
}

This is not really a tutorial on SQL statements. But still, I'll give you a quick overview on what exactly I did in the statements, and how you can use this code.

First of all, it's up to you to make sure that the users don't include single inverted commas into the username or password fields. You must absolutely make sure the user can only enter strings containing only characters a..z, A..Z and numbers. If you don't, you might run the risk of having SQL injection attacks on your code, especially if you're making an ASP.net Web Application.

To insert a new user:
INSERT INTO users(usr_Name, usr_Pass) VALUES('Rowan', 'ISeeSharp');

To verify whether a user exists:
SELECT COUNT(*) FROM users WHERE (usr_Name='Rowan') LIMIT 1;

To verify user credentials:
SELECT COUNT(*) FROM users WHERE (usr_Name='Rowan' AND usr_Pass='ISeeSharp') LIMIT 1;

There's no black magic in there. I'm just inserting users and counting records. Here's how you can use the wrapper - I used only the Add user and UserExists method. You can try the rest out yourself :)


            DbWrapper myWrapper = new DbWrapper("localhost", "CS",
                "iseesharp", "seesharper");
            myWrapper.Connect();

            myWrapper.AddUser("Rowan", "ISeeSharp");
            if (myWrapper.UserExists("rowan"))
            {
                Console.WriteLine("Something's weird here");
            }
            else
                if (myWrapper.UserExists("Rowan"))
            {
                Console.WriteLine("I exist, therefore I think!");
            }

            myWrapper.Disconnect();

This short piece of code instantiates a new DbWrapper, and passes it the required parameters to connect to my database. It adds a new user "Rowan" with the password "ISeeSharp" into the SQL Database. In between the Connect() and Disconnect() methods, you'll be able to use any of the provided methods in the wrapper. Make sure you disconnect after using the wrapper!

Cheers,
Rowy

I'm back!

2005-08-17T08:01:00.000+04:00

Yes. I am back.

I'm starting uni this year (after much debating with my inner selves) , and... well I'm doing Business IT. I really wanted to Computer Science and Eng. course, but well... Business doesn't look bad. Besides, I've still got programming modules in that - OOP starts in Semester 2, and they'll most probably have us to write

cout << "Hello World";

during semester one. Oh well, who cares! It's coding, coding, coding!

I hope you guys registered for the Google Jam. And also for the TopCoder Open... this is going to be fun, fun, FUN! YEAH BABE!

Anyway, there's much to say about C#. I've written some nice apps lately, but well... I've run across a few problems. I think I might need to convert my code to C (yes, I know, it's blasphemy, but well) - I wrote this neat program called "WordSearch", which actually builds a tree out of a dictionary (a tree where each node is connected to 26 other nodes) - but anyway, the first time I ran it, that piece of crap filled 57 megs of my memory straight away! Fuck man... Well after much mem optimization, I managed to bring the number down to 52 megs (believe me, I tried many things - I used a byte instead of a char, I killed strings, I did everything!) - but then I got this neat program called the CLR Analyzer, which actually tells you which part of your program is taking space - and well... yeah... never mind about which part is taking the space. I just can't use a class for a node. I'm going for C for this project.

Where can you find freelance programmers? Where can freelance programmers sign up for serious projects? I need cash... like everybody in this world - heh. But where to get it? Hmm... My coding skills - are they worth anything in this world? I wonder.

I want to open up a business. You can't much in here by working as coder. Sick sad un-OOP world.

Free Gmail Invites

2005-07-26T02:14:00.000+04:00

Yup, 50 free invites
[rowy loves you all, even if you don't C#]

I managed to set up Google Ads on my blog. Wasn't easy to make firefox and ie agree on a common template.

While strolling on the beach (yeah, I live at the beach. See my other blog), I've been cooking up some other really interesting C# projects (well, I'm still designing the recipe in my head). I was a bit pissed off about my console thingy - something like that already exists (thanks to Peter Jausovec for letting me know) but hey, there still are interesting things to do :D

Btw, for you guys out there... I'm giving out free Gmail invites. It's been nearly a year that I'm on Gmail, and I'm kinda tired of seeing all those invites... If you're interested, please leave a comment, or mail me at:

hehehe at gmail.com

[replace "hehehe" by "rowan.rishi" and "at" by "@"]
[you'll get the invite if you're smart enough to do that simple text replace]

An Interesting C# Project

2005-07-24T01:01:00.000+04:00

Missing the good ol' DOS console?
Let's revive the past!

I'm pretty nostalgic of MS-DOS... I was quite young when I first saw and used MS-DOS, which came with Basic. I used to copy examples from a Basic book, and then test them. That's when I began coding. I was five years old.

Languages have greatly evolved since Basic. C, C++, Pascal... and many many others. We're at a time when it'd take only a few months to develop a *really* cool console. However, when I say "cool", I don't mean a console using a single line Edit box, and a Multi line Edit box with a background on it. Hell, no.

I want a simple console, which is displayed on a real .Net console, with only a few inbuilt commands. The console would have a "Commands" directory, which would contain compiled .Net assemblies. The console, upon starting, would reflect inside of those dll's, and list out the commands available within them.

Of course, all commands would have to implement a "Command" interface, with an Execute method, which would accept as parameters an array of string (the list of arguments which the command should process), a Help method accepting a string as parameter and returning a string (which would provide help on a certain parameter), and a Description read-only property.

Does that sound too ambitious?

There are loads of problems that might arise during development of such a program. For example: what happens if there are two commands of the same name that exist?

Example:
Search.dll implements a Delete command
Files.dll Implements a Delete command

Could this issue be solved just like .Net deals with ambiguous names?

Does Search.Delete "expression" sound weird? Hmmm... it's something to look into. But for the moment, let me try to reflect inside assemblies, which aren't my own programs. That might be useful.

Explicit Typecasts

2005-07-23T21:03:00.000+04:00

Or also known as tranny-casts
[intermediate]

Implicit Typecasts are casts which occur when the compiler cannot directly treat one data type as another, and require "user intervention". By user intervention, I mean, user code :)

Trying to typecast a StreamReader into an ArrayList would be a bad idea. That's a typecasting that's not "meant to be" (would raise an InvalidCast Exception), and that's why the user should kick in his/her own code for it to happen.

As usual, I made another one of my useless classes, for the purpose of this tutorial. The Data class simply holds a name (string) and a DataValue (int). Also, I kicked in a few lines of code which would allow the data class to be typecasted as string (thus returning the name), or typecast as int (returning the DataValue). Check it out below:


/// <summary>
/// Simple class which holds a name (string) and a
/// value (int).
/// </summary>
public class Data
{
   private string name;
   private int dataValue;

   /// <summary>
   /// Instantiates a new Data class
   /// </summary>
   /// <param name="name">The name the data class 
   /// will hold</param>
   /// <param name="dataValue">The value the data
   /// class will hold</param>
   public Data(string name, int dataValue)
   {
       this.name = name;
       this.dataValue = dataValue;
   }

   /// <summary>
   /// Gets or Sets the name
   /// </summary>
   public string Name
   {
       get
       {
           return this.name;
       }
       set
       {
           this.name = value;
       }
   }

   /// <summary>
   /// Gets or sets the Data Value
   /// </summary>
   public int DataValue
   {
       get
       {
           return this.dataValue;
       }
       set
       {
           this.dataValue = value;
       }
   }

   /// <summary>
   /// Allow typecasting into string
   /// </summary>
   /// <param name="someData">The data class
   /// which needs to be typecasted</param>
   /// <returns>The name of the data class</returns>
   public static explicit operator string(Data someData)
   {
       string retValue = someData.name;
       return retValue;
   }

   /// <summary>
   /// Allow typecasting into int
   /// </summary>
   /// <param name="someData">The data class
   /// which needs to be typecasted</param>
   /// <returns>The value of the data class</returns>
   public static explicit operator int(Data someData)
   {
       int retValue = someData.dataValue;
       return retValue;
   }
}

The only part of this code that interests us is:


    /// <summary>
    /// Allow typecasting into string
    /// </summary>
    /// <param name="someData">The data class
    /// which needs to be typecasted</param>
    /// <returns>The name of the data class</returns>
    public static explicit operator string(Data someData)
    {
        string retValue = someData.name;
        return retValue;
    }

    /// <summary>
    /// Allow typecasting into int
    /// </summary>
    /// <param name="someData">The data class
    /// which needs to be typecasted</param>
    /// <returns>The value of the data class</returns>
    public static explicit operator int(Data someData)
    {
        int retValue = someData.dataValue;
        return retValue;
    }

Note that those two methods are static, and marked with the explicit and operator keywords. The first method simply contains code that is going to be executed if the user decides to typecast into a string. Note that the return type (i.e. the operation of the casting) is a string. The value in parameters is a Data class, i.e. the data class that's being typecasted into a string. The next lines of code are pretty easy. The name of the Data class is extracted by looking into the Data class passed into parameters, and this value returned (it's a string anyway).

And that's all there is to explicit typecasting. The second method does pretty much the same, but allows typecasting into an int (notice: the return type's an int). Here's how I explicitly typecasted my Data class into a string, and then an int.


     /// <summary>
     /// The main entry point for the application.
     /// </summary>
     [STAThread]
     static void Main(string[] args)
     {
         Data myData = new Data("Bebs", 19);

         Console.WriteLine((string)myData);
         Console.WriteLine(((int)myData).ToString());

         Console.ReadLine();

     }

Yup... and it works :) The complete source code can be found below:


using System;


namespace UselessStuff
{
  /// <summary>
  /// MultiParam App
  /// </summary>
  class UselessMain
  {
      /// <summary>
      /// The main entry point for the application.
      /// </summary>
      [STAThread]
      static void Main(string[] args)
      {
          Data myData = new Data("Bebs", 19);

          Console.WriteLine((string)myData);
          Console.WriteLine(((int)myData).ToString());

          Console.ReadLine();

      }
  }

  /// <summary>
  /// Simple class which holds a name (string) and a
  /// value (int).
  /// </summary>
  public class Data
  {
      private string name;
      private int dataValue;

      /// <summary>
      /// Instantiates a new Data class
      /// </summary>
      /// <param name="name">The name the data class 
      /// will hold</param>
      /// <param name="dataValue">The value the data
      /// class will hold</param>
      public Data(string name, int dataValue)
      {
          this.name = name;
          this.dataValue = dataValue;
      }

      /// <summary>
      /// Gets or Sets the name
      /// </summary>
      public string Name
      {
          get
          {
              return this.name;
          }
          set
          {
              this.name = value;
          }
      }

      /// <summary>
      /// Gets or sets the Data Value
      /// </summary>
      public int DataValue
      {
          get
          {
              return this.dataValue;
          }
          set
          {
              this.dataValue = value;
          }
      }

      /// <summary>
      /// Allow typecasting into string
      /// </summary>
      /// <param name="someData">The data class
      /// which needs to be typecasted</param>
      /// <returns>The name of the data class</returns>
      public static explicit operator string(Data someData)
      {
          string retValue = someData.name;
          return retValue;
      }

      /// <summary>
      /// Allow typecasting into int
      /// </summary>
      /// <param name="someData">The data class
      /// which needs to be typecasted</param>
      /// <returns>The value of the data class</returns>
      public static explicit operator int(Data someData)
      {
          int retValue = someData.dataValue;
          return retValue;
      }
  }
}

A few typeof(System.Random) thoughts

2005-07-23T02:06:00.000+04:00

I thought up of the advantages of coding vs. going out with someone:

Why is coding better than going out with someone?

1. Your programs use only your processing time.
2. Your programs use only your pc's resources.
3. Problems with a program can be solved by debugging.
4. Programs can be terminated any time you wish.
5. Programs don't mind when they execute with other programs.
6. Programs carry out all the commands you give them. Without bitching you.
7. Programs don't lie.
8. Big programming mistakes at worse end up with a system reboot or re-install.

I just went through shit to fix my blog's template. I added a few meta tags, and suddenly decided that maybe I should try viewing it in Internet Explorer. Yeah, well, hehe, I use Firefox.

The template was totally fucked up, with my menu below the main posts... Jesus Christ... spent about half an hour trying to find a balance between "good looking", "IE Compatible" and "Firefox Compatible". Well, template's fixed, and it all looks fine. I even managed to stretch the orange seperator...

I got a few ideas for new tutorials. I wonder when I'll have time to write them down though. I'll write about chaining constructors, implicit and explicit typecasts, some beginner's stuff about Interfaces, and maybe Datasets.

Ah, yeah. Datasets. Would that be beginner or intermediate? Hmm... Maybe I can cook up several tutorials on datasets - one for beginners and one for intermediates.

Also, I wanted to write something about NUnit, and good programming practises. Hmm... I'll do that soon enough.

Anyway, I've been reading (or trying to read) the CSharp 2.0 Specs document from Microsoft. I know, that's kinda old - I heard that CSharp 3.0 specs are coming out soon. I think that the new features of C# have been throughly detailed in many places throughout the web, but there's something I'd love to comment on, especially about the Generic types, and the Nullable types. I believe that C# code's really understandable, and pretty neat as well. However, with the introduction of the "<", ">", "?" and also "::" signs, the face of C# as we all know it is going to change. What I mean by "the face of C#" is how general C# code looks like. C# code with Generics and nullable types look pretty weird. Okay, maybe that's because I'm not used to see that kind of C# code... but there's something telling me that C# code might look very nasty in Whidbey.

On the whole, the CSharp 2.0 specs come round with loads of good news. Here's a quick summary of a few of the interesting things I saw:

1. Generics
I think that's one of the most publicized things about Whidbey. An example of the use of Generics could be an Arraylist, that's forced to accept only one kind of object, through the use of Generics. I.e. You can create an arraylist that accepts only strings, or integers. Writing generic classes, however, might get a little bit confusing.

2. Nullable types
Well, simply put, a nullable type is a data type which has, apart from its value, a boolean value indicating whether the value on it has been set or not. So you can perform checks on variables, to see whether they've been initialized or not, through the HasValue property.

3. Easier implementation of IEnumerable
Those of you who think that it's troublesome to implement IEnumerable (like me, for example), will be overjoyed to hear that there's now a much easier method to do it, thanks to the yield newly-introduced yeild break and yeild return keywords.

Hmm... well... there's more to Whidbey than what I've described here, namely anonymous methods and so on, but seriously, it's getting kinda late here. I think I'll go to sleep for a change.

Have a nice day, and may the code be with you.

Situation of Programmers in Mauritius

2005-07-22T22:14:00.000+04:00

Every little kid out of high school wants to study computer science and engineering in university. However, many of them are just into comp. science because it's something popular to study. Yes, it's a "popular" subject.

I wouldn't recommend computer science and engineering to people who just don’t know what they’re going to do later. You’ll end up hating the coding, and coding is what you’ll spend your time doing.

Personally, I eat, drink, sleep and live with code. I don’t think I’ll get bored of coding someday. Coding… or designing software / classes. But you might. And you’ll hate your work, the company you work for, and your life in the end.

Anyway, you might also turn out to be a great coder, and actually enjoy coding. Who knows? But don’t rush into computer science and engineering just because it’s the only best thing to study right after agriculture.

Now, a little update for you guys. As soon as you’re out of university, you won’t be earning a lot. Nope. A certain company in Mauritius recruited a few programmers (that was last year), and paid them Rs 8000 / month. That’s about US$ 280 a month. After six months of training, their salary was raised to Rs 11, 000 – Rs 12,000 (US$ 385 - US$ 420). I’ve heard that another company (located in the cybertower) pays its programmers US$ 525 a month (Rs 15,000). Is there really a future for programming in here?

The main argument of most employers is – “Mauritian programmers just can’t code properly.”

True. Before becoming a good programmer, what you need is experience. As a friend of mine once said – “Fucking muppets need fucking training”. To all of you guys who chose comp. sci and eng. just because it’s a cool thing to study – you’re not going to go far if you don’t start moving your butt.

Also, if we didn’t have so many people studying computer science, we’d probably be off with a smaller number of programmers, but more motivated and skilled.

Good Programming

Good programming practices are what will make of you a better coder. You can either learn the hard way – i.e. code, code, and keep coding. You’ll eventually understand why people use try’s and catch’es. You’ll understand why people put comments in their code, why people use NUnit. You could also start learning about good programming practices right now. There are tips and hits everywhere on the net.

The Substandard Programming Nation

As someone previously pointed out to me, the education system in here is all about spoon-feeding. That’s why most Mauritian programmers would back off as soon as they hear that they got to implement a shortest-path algorithm on a graph.

“Hell, isn’t there a method to do that in C#?”

Jesus fucking Christ. C# does have a lot of methods, but they’re here to make your life easier, not to do all the work. What, did you expect to find a method WankMe()? Well, FuckYou(). You need to work on your coding skills. Else, Mauritius will only be a god-damned sub-standard outsourcing paradise destination, with only sub-standard programmers who don’t know that there needs to be a try and a catch statement when trying to open a file.

That said, let us not forget that there really are some good coders in this country. People who are really motivated to learn more, sharpen their skills, and become good and better coders.

It’s all about the code.

Sex and C#

2005-07-22T02:47:00.000+04:00

Single 19 (soon to be 20) year old male, looking for female of the same age range for friendship or better, preferably living in Mauritius, sharing same passions about C#. Must understand polymorphism, be able to use enumerated types, must know how to chain constructors and use indexers, must have a vague idea (or better) of what MSIL could be and must know how to use different threading models in C#. Preference will be given to candidates who have knowledge of ASP.Net and to candidates who have big breasts.

Any intimate encounter will occur in XML.

Yet another cool and useful feature

2005-07-22T00:31:00.000+04:00

The Params keyword
[Beginner]

The params keyword could be one of the coolest features of C-Sharp, if you haven't heard of it yet. Simply put, it allows you to enter multiple parameters of a same type. An alternative to this could be the use of an array - i.e. create a method that accepts an array of a certain kind of objects, but that's really troublesome. Here, check the code out - it's pretty simple and straightforward:


using System;

namespace MultiParams
{
/// <summary>
/// MultiParam App
/// </summary>
class MyClass
{
  /// <summary>
  /// The main entry point for the application.
  /// </summary>
  [STAThread]
  static void Main(string[] args)
  {
      Console.WriteLine(AddAll(43, 94, 29, 958, 3283, 9285).ToString());
      Console.ReadLine();
  }

  public static double AddAll(params int[] numbers)
  {
      double total = 0;

      foreach(int i in numbers)
      {
          total += i;
      }

      return total;
  }
}
}

What really interests us is the AddAll method. Let's have a closer look:


public static double AddAll(params int[] numbers)
{
   double total = 0;

   foreach(int i in numbers)
   {
       total += i;
   }

   return total;
}

There's nothing particular in that method, apart from the "params" keyword used in the parameters. It's pretty strightforward. The use of the params in the parameters allows users to pass multiple values (in this case, multiple int's) of the same type - they all get kicked into an array of that object type (in this example, an array of int, which I named "numbers"). Using this function gets really easy now. All you have to do is to call the AddAll method with as much number of integer parameters as you want! Et voilà! Rien de plus façile! I called the AddAll method, and passed in a few numbers - and called the ToString() method.

Now, think of your own ways to make a good use of the params keyword ;)

A few basic things

2005-07-21T23:33:00.000+04:00

Decimal Places
[Beginner]

There are quite a few things to know before really getting the hang of C#, and I believe that learning about how to format numbers that need to be output is something pretty basic, that many programmers disregard. However, here's a basic tutorial about controlling the number of decimal places that a decimal type displays.

Let's move on directly to the code. It's simple. Nothing complicated to understand. Check it out:


using System;
using System.Globalization;

namespace NumberFormat
{
   /// <summary>
   /// MultiParam App
   /// </summary>
   class Class1
   {
       /// <summary>
       /// The main entry point for the application.
       /// </summary>
       [STAThread]
       static void Main(string[] args)
       {
           NumberFormatInfo myFormat = new NumberFormatInfo();
                   double d = 15.6781005479;

           for (int i=0; i<=10; i++)
           {
               myFormat.NumberDecimalDigits = i;
               Console.WriteLine(i.ToString() +
                   " decimal digit(s): \t\t"+d.ToString("N", myFormat));
           }

           Console.ReadLine();
       }
   }
}

Notice that I've included System.Globalization in the usings. This is a namespace that is required in order to use the NumberFormatInfo class.

What I did was basically to instantiate a NumberFormatInfo class, and play with the NumberDecimalDigits property (which I kept incrementing). Watch the results on a console :) Also, note the use of the overloaded ToString() method, in which I passed two parameters, namely a string ("N"), and the NumberFormatInfo class that I instantiated.

Hope this little code snippet helps!

C# News

2005-07-21T22:48:00.000+04:00

The graph below shows the number of times programmers of different languages got dates or were turned down while asking for a date.

C# programmers enjoy a more sexually-active life. Experts can only agree.

After an interview with Jack (fake name), an application optimizer (he uses ASM), we found out the real truth behind the lives of programmers who made bad choices.

"I was under a lot of stress at home. I kept having fights with my wife, Tabitha (fake name). I knew it was because of it [the programming language I used]. I had to change, but I wasn't very sure which one. I went for VB. That, I think, was the worse decision of all my life."

Like Jack, many programmers suffered the choices of their language. Ben (fake name), a C++ programmer earning US$4000 per month, was caught by his wife using Java at home. "She couldn't believe it. She sent me the divorce papers one week later," confides Ben, still trying to recover from his loss.

Some, however, seem to have understood what a programmer's life was all about. Sonya (fake name), a 24 year old hottie, agreed to share information on her programming past with us.

"Before, I couldn't even get laid. Guys wouldn't even look at me. I was a Java programmer." Her sad expression reflects her unhappy past. "Fortunately, a friend of mine introduced me to C#. I easily got the hang of it, and found the language very comfortable to use." We had doubts about Sonya's claims on her inactive sexual life, when she explained to us: "I couldn't believe it. After two months of using C#, my breasts started to grow larger, and my butt and thighs more firm. It was incredible!". Sonya now enjoys a peaceful life with Brandon (fake name), also a C# programmer. They're expecting a baby this November. "If it's a boy, we're gonna call him Whidbey," the happy couple told us.

Indexers

2005-07-21T00:45:00.000+04:00

Indexers in C#
Intermediate

I've been up to nothing good on C#, and I thought I'd post something about indexers on C#. Being able to provide a collection class with an indexer could be a real cool thing, if you know how to do it :)

Indexers allow your class(es) to be treated like arrays - an "index" is passed in between square brackets, and an object is returned. Just like an arraylist. Or an array :)

To begin my second C# tutorial, please take a look at the utterly useless Item class:


  /// <summary>
  /// Just a dummy class named Item, with a few properties.
  /// </summary>
  public class Item
  {
      //Name represents the name of the item class
      private string name;
      //Data represents a data value
      private string data;

      /// <summary>
      /// Constructor for the Item class.
      /// </summary>
      /// <param name="name">String representing the name of the class</param>
      /// <param name="data">Data the class will hold</param>
      public Item(string name, string data)
      {
          this.name = name;
          this.data = data;
      }

      /// <summary>
      /// Gets or sets the name of the class
      /// </summary>
      public string Name
      {
          get
          {
              return this.name;
          }
          set
          {
              this.name = value;
          }
      }

      /// <summary>
      /// Gets or sets the it's data value
      /// </summary>
      public string Data
      {
          get
          {
              return this.data;
          }
          set
          {
              this.data = value;
          }
      }

      // - Little Note -
      // It's always good to use properties instead of
      // directly exposing a variable as public
  }

Well, as you can see, the Item class doesn't do anything particular. Of course, it's just a dummy class, created for the purpose of this tutorial. What would interest you would be the ItemHolder class - a class that can actually accept a collection of items. Check out the code below:


  /// <summary>
  /// A class that can hold Items
  /// </summary>
  public class ItemHolder
  {
      //This arraylist will actually contain all the items
      private ArrayList itemList;

      /// <summary>
      /// Creates a new instance of the ItemHolder class, which is able
      /// to hold multiple items.
      /// </summary>
      public ItemHolder()
      {
          itemList = new ArrayList();
      }

      /// <summary>
      /// Indexer for the ItemHolder class
      /// </summary>
      public Item this[int pos]
      {
          get
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //typecast to Item, and return
                  return ((Item)this.itemList[pos]);
              }
          }

          set
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //Make a type check, just in case
                  if (value.GetType() == typeof(Item))
                  {
                      Exception myExcp =
                          new Exception("You can only assign objects of the type \"Item\"");
                      throw myExcp;                          
                  }
                  else
                  {
                      this.itemList[pos] = value;
                  }
              }              
          }
      }

      /// <summary>
      /// Adds an item to the collection of Items
      /// </summary>
      /// <param name="someItem"></param>
      public void AddItem(Item someItem)
      {
          //Check whether the item's not null
          if (someItem != null)
          {
              this.itemList.Add(someItem);
          }
          else
          {
              Exception myExcp =
                  new Exception("Null objects are not allowed in this collection");
              throw myExcp;
          }
      }

      /// <summary>
      /// Returns a count of the total number of items inside
      /// the this object
      /// </summary>
      public int Count
      {
          get
          {
              return this.itemList.Count;
          }
      }
  }

Do take a closer look at the indexer:


      /// <summary>
      /// Indexer for the ItemHolder class
      /// </summary>
      public Item this[int pos]
      {
          get
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //typecast to Item, and return
                  return ((Item)this.itemList[pos]);
              }
          }

          set
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //Make a type check, just in case
                  if (value.GetType() == typeof(Item))
                  {
                      Exception myExcp =
                          new Exception("You can only assign objects of the type \"Item\"");
                      throw myExcp;                          
                  }
                  else
                  {
                      this.itemList[pos] = value;
                  }
              }              
          }
      }

This is what we're interested in. Disregard the code - it's just exceptions I couldn't resist throwing just in case the wrong type's being used (I'm forcing the use of Item types of objects inside the collection). The indexer doesn't get more complicated than


public <DataType> this[<DataType> <VariableName>]
{
  get
  {
  }

  set
  {
  }
}

Where the first DataType represents the return type of the indexer, the second DataType the type of the value passed into the square brackets, and VariableName the name of the variable that you want to use for the value that the user has provided. There's also a get and a set property (the accessors) which enable you to execute different code, depending on whether the user's only reading the value, or modifying it.

Now, for the code inside the indexer -

Notice that my indexer directly returns an Item (saves you the typecasting, heh), given an int - which represents the index value of the Item inside of my collection. When the user tries to get an item, the get part of the accessor is executed. I made a little check on the value of the index being passed. Passing -1 would most certainly raise an exception - as well as passing a value outside of the bounds of the collection.

In the set accessor, I had to carry out even more checks - apart from the bounds checking, I also made a little check on the type of value being set. I modified the code a little bit, because using "is" creates more solid code than using GetType() (see below). The is keyword checks for parent objects, and the GetType() only checks for the type. Below is the code that I replaced:


                  //Make a type check, just in case
                  if (value is Item)
                  {
                      Exception myExcp =
                          new Exception("You can only assign objects of the type \"Item\"");
                      throw myExcp;                          
                  }
                  else
                  {
                      this.itemList[pos] = value;
                  }

Instead of:


                  //Make a type check, just in case
                  if (value.GetType() == typeof(Item))
                  {
                      Exception myExcp =
                          new Exception("You can only assign objects of the type \"Item\"");
                      throw myExcp;                          
                  }
                  else
                  {
                      this.itemList[pos] = value;
                  }

The set accessor first checks whether the index passed resides within the collection's bounds (more than -1, less than the count of number of items), and then checks for the type being set; after modification of the code, an object derived from Item will also be accepted in the Indexer.

Note that I also implemented an AddItem method, which allows users to kick in Items into the collection (without which, this whole class would be useless), and a Count property, which allows users to get the number of total items inside of the class. Of course, I could've elaborated, implemented a Delete method and so on, but that's up to you. Below is the code that I used to make the Item and ItemHolder classes work:


      [STAThread]
      static void Main(string[] args)
      {
          Item myItem1 = new Item("Rowan",
              "Shit happens");

          Item myItem2 = new Item("Vidi",
              "Life is a bitch, and then you die");

          Item myItem3 = new Item("Natasha",
              "Good girls go to heaven, Bad girls get what they want");
        
          ItemHolder holder = new ItemHolder();
          holder.AddItem(myItem1);
          holder.AddItem(myItem2);
          holder.AddItem(myItem3);

          for (int i=0; i<=holder.Count-1; i++)
          {
              Console.WriteLine("Name: " + holder[i].Name);
              Console.WriteLine("Quote: " + holder[i].Data);
              Console.WriteLine();
          }

          Console.ReadLine();
      }

Here's the complete code for the tutorial:


using System;
using System.Collections;

namespace Indexer
{
  /// <summary>
  /// Comments are pretty useful, even in tutorials
  /// </summary>
  class IndexerTest
  {
      /// <summary>
      /// Main entry pt. for app.
      /// </summary>
      [STAThread]
      static void Main(string[] args)
      {
          Item myItem1 = new Item("Rowan",
              "Shit happens");

          Item myItem2 = new Item("Vidi",
              "Life is a bitch, and then you die");

          Item myItem3 = new Item("Natasha",
              "Good girls go to heaven, Bad girls get what they want");
        
          ItemHolder holder = new ItemHolder();
          holder.AddItem(myItem1);
          holder.AddItem(myItem2);
          holder.AddItem(myItem3);

          for (int i=0; i<=holder.Count-1; i++)
          {
              Console.WriteLine("Name: " + holder[i].Name);
              Console.WriteLine("Quote: " + holder[i].Data);
              Console.WriteLine();
          }

          Console.ReadLine();
      }
  }

  /// <summary>
  /// Just a dummy class named Item, with a few properties.
  /// </summary>
  public class Item
  {
      //Name represents the name of the item class
      private string name;
      //Data represents a data value
      private string data;

      /// <summary>
      /// Constructor for the Item class.
      /// </summary>
      /// <param name="name">String representing the name of the class</param>
      /// <param name="data">Data the class will hold</param>
      public Item(string name, string data)
      {
          this.name = name;
          this.data = data;
      }

      /// <summary>
      /// Gets or sets the name of the class
      /// </summary>
      public string Name
      {
          get
          {
              return this.name;
          }
          set
          {
              this.name = value;
          }
      }

      /// <summary>
      /// Gets or sets the it's data value
      /// </summary>
      public string Data
      {
          get
          {
              return this.data;
          }
          set
          {
              this.data = value;
          }
      }

      // - Little Note -
      // It's always good to use properties instead of
      // directly exposing a variable as public
  }


  /// <summary>
  /// A class that can hold Items
  /// </summary>
  public class ItemHolder
  {
      //This arraylist will actually contain all the items
      private ArrayList itemList;

      /// <summary>
      /// Creates a new instance of the ItemHolder class, which is able
      /// to hold multiple items.
      /// </summary>
      public ItemHolder()
      {
          itemList = new ArrayList();
      }

      /// <summary>
      /// Indexer for the ItemHolder class
      /// </summary>
      public Item this[int pos]
      {
          get
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //typecast to Item, and return
                  return ((Item)this.itemList[pos]);
              }
          }

          set
          {
              //Check whether the position is within the arraylist's index bounds
              if ((pos > this.itemList.Count-1) || (pos < 0))
              {
                  Exception myExcp =
                      new Exception("Index was out of bounds of array");
                  throw myExcp;
              }
              else
              {
                  //Make a type check, just in case
                  if (value is Item)
                  {
                      Exception myExcp =
                          new Exception("You can only assign objects of the type \"Item\"");
                      throw myExcp;                          
                  }
                  else
                  {
                      this.itemList[pos] = value;
                  }
              }              
          }
      }

      /// <summary>
      /// Adds an item to the collection of Items
      /// </summary>
      /// <param name="someItem"></param>
      public void AddItem(Item someItem)
      {
          //Check whether the item's not null
          if (someItem != null)
          {
              this.itemList.Add(someItem);
          }
          else
          {
              Exception myExcp =
                  new Exception("Null objects are not allowed in this collection");
              throw myExcp;
          }
      }

      /// <summary>
      /// Returns a count of the total number of items inside
      /// the this object
      /// </summary>
      public int Count
      {
          get
          {
              return this.itemList.Count;
          }
      }
  }


}

IComparer Interface

2005-07-14T18:01:00.000+04:00

Sorting out your problems
[Intermediate]

I made a small but cute class for Person - there's Name, which identifies the person's name and there's Age, which represents the person's age.

Creating multiple instances of the persons class would require me to kick them all into an ArrayList - which I did. I had a precise idea in mind: I wanted the ArrayList to sort my list of Persons by either name or age.

This is when I learnt about the IComparer and IComparable interfaces. However, in this tutorial, we're going to focus on the IComparer interface. Please note that the IComparer interface requires the use of System.Collections. Below is the code for my Person class.


/// <summary>
/// The Person class contains the name of the person and the age of
/// the person.
/// </summary>
public class Person
{
 //private string holding person's name
 private string name;

 //private int holding person's age
 private int age;

 /// <summary>
 /// Creates a new Person object with the specified name and age.
 /// </summary>
 /// <param name="name">The name of the person</param>
 /// <param name="age">The age of the person</param>
 public Person(string name, int age)
 {
     this.name = name;
     this.age - age;
 }

 /// <summary>
 /// Gets or sets the name of the person
 /// </summary>
 public string Name
 {
     get
     {
         return this.name;
     }
     set
     {
         this.name = value;
     }
 }

 /// <summary>
 /// Gets or sets the age of the person
 /// </summary>
 public int Age
 {
     get
     {
         return this.age;
     }
     set
     {
         this.age = value;
     }
 }
}

A class implementing the IComparer interface can be passed onto the ArrayList.Sort method to provide the latter with a means of comparing two values. Why compare two values? Simple, because the QuickSort algorithm (which the arraylist obviously implements) works by consecutively comparing two values. Any quicksort algorithm can easily be adapted on a set of data, given the comparing method.

What's left to do is to create a class which implements the IComparer method. Also, we might wish to allow for "customization" of that class, i.e. allow different means of sorting. To do this, I created an enumerated type which would hold the different types of sorting. See the code below:


/// <summary>
/// Enumerator for types of person sorting
/// </summary>
public enum SortPersonsBy {byName, byAge};

/// <summary>
/// Person Sorting Class, implements IComparer
/// </summary>
public class SortPersons : IComparer
{
   //Private value holding the Persons sort type
   private SortPersonsBy sortType;

   /// <summary>
   /// Creates a new instance of the SortPersons class. Use this class to specify sorting
   /// methods for arraylists filled with only persons.
   /// </summary>
   /// <param name="sortingType"></param>
   public SortPersons(SortPersonsBy sortingType)
   {
       this.sortType = sortingType;
   }

   /// <summary>
   /// Gets or sets the SortPersonsBy type.
   /// </summary>
   public SortPersonsBy SortType
   {
       get
       {
           return this.sortType;
       }
       set
       {
           this.sortType = value;
       }
   }

   /// <summary>
   /// Implementation of the Compare method, required for the IComparer class
   /// </summary>
   /// <param name="x">First object</param>
   /// <param name="y">Second object</param>
   /// <returns>An int, which is the value obtained when the two objects
   /// have been compared.</returns>
   public int Compare(object x, object y)
   {
       //Check whether x and y are both Person classes.
       if ((x is Person) && (y is Person))
       {
           //Some little typecasting
           Person a = (Person)x;
           Person b = (Person)y;

           //Check the sorting type
           if (this.sortType == SortPersonsBy.byName)
           {
               //Use the native string.CompareTo method
               return (a.Name.CompareTo(b.Name));
           }
           else
           {
               //Use the native int.CompareTo method
               return (a.Age.CompareTo(b.Age));
           }
       }
       else
       {
           //return 0 if x or y are of wrong type
           return 0;
       }
   }

}

The code above contains an enumerated type and a SortPersons class, which implements the IComparer interface. The SortPersons class has a SortPersonsBy property, which allows the user to choose between sorting by name and sorting by age.

When the ArrayList.Sort() method is called with a SortPersons class, the Compare method is executed numerous times. First of all, my Compare method checks for the types of objects - i.e. whether they are persons or not. If one of them isn't a Person class, the Compare method returns 0. If they both are Person classes, the type of sorting is checked. If the type of sorting is set to "byName", the string's CompareTo method is called using the two person's names; if the type of sorting is set to "byAge", the int's CompareTo method is called using the two person's ages.

And that's it! Here's the full source code of my app:


using System;
using System.Collections;

namespace SortProject
{
 /// <summary>
 /// The Main Class
 /// </summary>
 class MainClass
 {
     /// <summary>
     /// Con. App. Entry Pt.
     /// </summary>
     [STAThread]
     static void Main(string[] args)
     {
         //Create a few persons
         Person a = new Person("Rowan", 19);
         Person b = new Person("Rishi", 19);
         Person c = new Person("Vidisha", 18);
         Person d = new Person("Dominique", 21);
         Person e = new Person("Arvind", 22);
         Person f = new Person("Mom", 49);
         Person g = new Person("Visitor", -1);

         //Create a SortPersons object, and set the sorting type to "byName"
         SortPersons mySortingMethod = new SortPersons(SortPersonsBy.byName);
      
         //Create a new arraylist and kick in the persons
         ArrayList someList = new ArrayList();
         someList.Add(a);
         someList.Add(b);
         someList.Add(c);
         someList.Add(d);
         someList.Add(e);
         someList.Add(f);
         someList.Add(g);
         someList.Sort(mySortingMethod);
    
         Console.WriteLine("Sorting persons by name: \n\n");
      
         //Display the list of persons
         for (int i=0; i<= someList.Count-1; i++)
         {
             Person somePerson = ((Person)someList[i]);
             Console.WriteLine("Person Name: " + somePerson.Name +
                               "\t\tPerson Age: " + somePerson.Age);
         }

         Console.WriteLine("Sorting the persons by age: \n\n");
      
         //Set the sorting type to "byAge" and resort the ilst
         mySortingMethod.SortType = SortPersonsBy.byAge;
         someList.Sort(mySortingMethod);
      
         //Re-Display the list of persons
         for (int i=0; i<= someList.Count-1; i++)
         {
             Person somePerson = ((Person)someList[i]);
             Console.WriteLine("Person Name: " + somePerson.Name +
                               "\t\tPerson Age: " + somePerson.Age);
         }

         Console.ReadLine();
     }
 }

 /// <summary>
 /// The Person class contains the name of the person and the age of
 /// the person.
 /// </summary>
 public class Person
 {
     //private string holding person's name
     private string name;

     //private int holding person's age
     private int age;

     /// <summary>
     /// Creates a new Person object with the specified name and age.
     /// </summary>
     /// <param name="name">The name of the person</param>
     /// <param name="age">The age of the person</param>
     public Person(string name, int age)
     {
         this.name = name;
         this.age = age;
     }

     /// <summary>
     /// Gets or sets the name of the person
     /// </summary>
     public string Name
     {
         get
         {
             return this.name;
         }
         set
         {
             this.name = value;
         }
     }

     /// <summary>
     /// Gets or sets the age of the person
     /// </summary>
     public int Age
     {
         get
         {
             return this.age;
         }
         set
         {
             this.age = value;
         }
     }
 }

 /// <summary>
 /// Enumerator for types of person sorting
 /// </summary>
 public enum SortPersonsBy {byName, byAge};

 /// <summary>
 /// Person Sorting Class, implements IComparer
 /// </summary>
 public class SortPersons : IComparer
 {
     //Private value holding the Persons sort type
     private SortPersonsBy sortType;
  
     /// <summary>
     /// Creates a new instance of the SortPersons class. Use this class to specify sorting
     /// methods for arraylists filled with only persons.
     /// </summary>
     /// <param name="sortingType"></param>
     public SortPersons(SortPersonsBy sortingType)
     {
         this.sortType = sortingType;
     }

     /// <summary>
     /// Gets or sets the SortPersonsBy type.
     /// </summary>
     public SortPersonsBy SortType
     {
         get
         {
             return this.sortType;
         }
         set
         {
             this.sortType = value;
         }
     }

     /// <summary>
     /// Implementation of the Compare method, required for the IComparer class
     /// </summary>
     /// <param name="x">First object</param>
     /// <param name="y">Second object</param>
     /// <returns>An int, which is the value obtained when the two objects
     /// have been compared.</returns>
     public int Compare(object x, object y)
     {
         //Check whether x and y are both Person classes.
         if ((x is Person) && (y is Person))
         {
             //Some little typecasting
             Person a = (Person)x;
             Person b = (Person)y;

             //Check the sorting type
             if (this.sortType == SortPersonsBy.byName)
             {
                 //Use the native string.CompareTo method
                 return (a.Name.CompareTo(b.Name));
             }
             else
             {
                 //Use the native int.CompareTo method
                 return (a.Age.CompareTo(b.Age));
             }
         }
         else
         {
             //return 0 if x or y are of wrong type
             return 0;
         }
     }

 }

}

Introduction

2005-07-14T17:26:00.000+04:00

Do You See Sharp?

Welcome to my Blog! It's not exactly a blog, it's more of a tutorial-oriented consecutive series of html pages organised into a blog.

I don't really have time (nor the necessary funds :( ) to buy webspace - but hey! Blogger's here to help :)

Anyway, let me post this and move on to the first C# tutorial!

Rowy