Thread: Easy code question

So, I wrote this:

Code:

 
#include <stdio.h>
#include <ctype.h>

int main() {
    char m;
    while(m=getchar() !='\n') {
              if(isdigit(m))  printf("There is a number in line");
    }

}

I thought this will go char by char and check if any char is a digit in line. So Im wondering why it doesnt work?

Your problem is due to operator precedence. "!=" has higher precedence than "=". Look at this bit:

Code:

m=getchar() !='\n'

This is essentially equivalent to this:

Code:

m= (getchar() !='\n')

"getchar()" reads a character and checks if it is not equal to a newline. The result of this comparison (true or false) is then stored in the variable "m". This is clearly not the behavior you are expecting.

To store the result of "getchar()" in "m" and then compare that value against the newline, you need to explicitly group the "m = getchar()" part:

Code:

(m=getchar()) !='\n'

Thank you both for help,i understand now.