Stumped with IF

[Ameki]

Hi Guys, I'm new here and was wondering if anyone can help me on this one problem I'm having, or explain whats wrong so I can at least 'try' and sort it out.

I've made an attempt at a tic tac toe game, everything's going well with it apart from this one part (as far as I can see) it's to do with the computer picking a random number. It generates a number but it overwrites whats previously there when it shouldn't.

void AI(){
	int randomnumber;
	srand (time(NULL));
	while(!Player){
		randomnumber = rand() % 8;
		if((BoardNumbers[randomnumber] != 'X') || (BoardNumbers[randomnumber] != 'O' )){
			BoardNumbers[randomnumber] = 'X';
			BoardWin();
			DrawBoard();
			Player = true;
		}
	}
}

If needed I can post the whole code. Many Thanks,

Ameki

[Moschops]

Your code will overwrite if one of the following two things is TRUE:

What's there already is not a X
What's there already is not a O

Can you think of ANY value for which both of those conditions will be false? No. At least one of them be true, no matter what value is there already.

[Ameki]

Thanks for the reply Moschops, going from your:
What's there already is not a X
What's there already is not a O

There's already a character there going from 1-9, its in a char array which is set globally. I've tried taking the AI out and just playing as a player 1 vs player 2 thing and it works fine, granted it was using a switch statements though.

[Niven]

What Moschops was saying is that the || needs to be a &&. || means or so the code is executed if (BoardNumbers[randomnumber] != 'X') OR (BoardNumbers[randomnumber] != 'O' ) If there is already a value there, like X, then it's not equal to O so the code will execute and vice versa for if the value there is O. By changing it to and(&&) instead of or, the code will only execute when both (not either like with or) of the conditions are true. This way, if there's an X there then one of the conditions is false and the code won't execute. Same goes for if there's an O there

[Ameki]

After putting that in the code works, sat back and pondered and realized what Moschops meant. Sorry for that, think I'll do a quick skim through operators again.

Ameki