C - error: ignoring return value of scanf?

Question

I'm only a few days into C programming, so I am not quite sure what's wrong with this code:

#include <stdio.h>

int main(int argc, char * argv[]) {
    int sides;
    printf("Please enter length of three sides :\n");
    scanf("%d", &sides);
    return 0;
}

The error message I receive is as follows:

ignoring return value of scanf

What am I doing wrong here, and what can I do to fix it?

Answer 1

You might code

if (scanf("%d", &sides) >0) {
    printf("you want %d sides.\n", sides);
} 
else printf("You did not enter any number.\n");

The scanf function (please follow the link) has several roles

1. it is expecting some input and could modify the variables you passed by address to it
2. it is returning the number of successfully input items