Thread: Comma operator

Hello all,

Code:

#include <stdio.h>
int main()
{
    printf("How is "), printf("this "), printf("possible."), getchar();
    return 0;
}

This code seems to work fine. So the meaning of the 'comma' operator seems to be different. Could anyone give me definitation of 'comma' operator in C? This seems to be like programming Prolog

Thanks

Harish

It executes all the statements and returns the right-most statement, basically.
In your statement, what would be returned is the value of getchar(). That is, if you wanted to save it. Otherwise it acts like different statements separated with ;.

It is particularly useful in for loops when you are trying to iterate or test for two things at the same time:

Code:

int i, count;
for(i = 0, count =5;i < MAX;i++,count++);

Other than that I think there are probably a couple of situations when you could be legitimately using it, but it generally just obfuscates your code.