Problems with scanf

Question

I'm having problems with this snippet of code:

   while(scanf("%d",&numOfPlayers)!=1){
        printf("Please enter the right number of players");    
    }

My purpose is to read a number from the user, and keep asking as long as the input isn't an int. When I run this snippet and input 'r' for example, I get stuck in an infinite loop. What might be the problem, and how can I improve it?

Answer 1

Try scanning for a string into a buffer and then searching that string for your number with sscanf().

Answer 2

If scanf() can't read the input, it actually doesn't read it, so it reads the same input over and over again in your example. You can discard the invalid input like this:

while(scanf("%d",&numOfPlayers)!=1){
  scanf("%s");
  printf("Please enter the right number of players\n");
}

Answer 3

From the comp.lang.c FAQ: Why does everyone say not to use scanf? What should I use instead?