switch or ifs

[jax666999]

I am trying to check wheather certain combinatins of characters occur in an array can I use a switch or do I have to use multiple ifs and if/elses

[MrHutch]

Personal preference.

If I'm using lots and lots of if statements, it starts to look a bit ugly. I tend to use switch statements in those situations.

For smaller checks, I always use if.

[jax666999]

this array has 9 elements and I am looking for combinations of three there are sixteen possible combinations I need to find if and when they occur so a switch would be better but I need to know how to start this switch and if there is an even easier way

[MrHutch]

What are you doing, Tic-Tac-Toe?

[jax666999]

yes it is

[jax666999]

its tic-tac-toe and Im splitting it up into several functions the one I am asking about checks wheather the game the game has ended or not and acts accordingly

[MrHutch]

You probably won't need 16 checks then.

There are 16 win conditions (8 per player) but the same check can be used for each.

Say that your array of 9 represents the board like this:

[0][1][2]
[3][4][5]
[6][7][8]

An example of a winning row is if 0,1 and 2 are all O or all X. So you can check them all in one statement:

if (board[0] == board[1] == board[2])
{
   return board[0];
}

You could even store all of the winning positions sequentially in an array, and loop through that, effectively reducing your original 16 if statements down to just one:

int win_array[24] = {0,1,2,
                     3,4,5,
                     6,7,8,
                     0,3,6,
                     1,4,7,
                     2,5,8,
                     0,4,8,
                     2,4,6};

for (int i=0; i <= 21; i+=3)
{
   if(board[win_array[i]] == board[win_array[i]+1] == board[win_array[i]+2])
   {
      return board[win_array[i]];
   }
}

By returning the value in the check when there is a win, you can tell who's won in your function call:

if(HasWon() == 'O')
{
   cout << "O has won";
}
else if (HasWon() == 'X')
{
   cout << "X has won";
}
else
{
   // No winner yet
}

Hope this is of some use.

[jax666999]

would this work
if (gameBoard[1] == gameBoard[4] == gameBoard[7] == P1_CHAR || P2_CHAR)
{
gameState = 1 || 2;
}


P1_CHAR being X
P2_CHAR being O
and gameState = 1 if X wins 2 if O wins

[Lachlan Easton]

if (board[0] == board[1] == board[2])

Correct me if I'm wrong but I don't think that would work. The operator == returns a bool value so say board[0] - [1] - [2] all equal 'a' then the first "==" will check

board[0] == board[1]

which is true so then the second one will check

true == board[2]

which is false.

[jax666999]

if board[2] does infact equal a as do [0] and [1] why wouldnt the second check be true

what I was really worrying about not working is the P1_CHAR || P2_CHAR and the gameState = 1 || 2

[Lachlan Easton]

In short no. P1_CHAR || P2_CHAR will return true if either are non zero.
gameState = 1 || 2
Will make gameState true if either are non zero.

[jax666999]

I want it to return the appropriate value (1 or 2) depending on which char is in the three squares (gameBoard[0], [1], [2]) how can I get this to happen

[Lachlan Easton]

if(
gameBoard[0]==gameBoard[1] &&
gameBoard[0]==gameBoard[2] && 
gameBoard[0]==P1_CHAR )

will be true if all values are equal to P1_CHAR so return 1.
Then do an else if to check them against P2_CHAR

[jax666999]

I see that this would work but this would turn my 90 lines of code into about 150

[jax666999]

yep 153 lines and there is still one more function to write

[MrHutch]

Yeah, Lachlan, you're probably right.

I didn't have a compiler handy to test that out at the time. It's easily fixed by adding an 'and' clause in there:

if(board[0] == board [1]  && board[1] == board[2])
{
   return board[0];
}