C Program – Check Whether a Number is Positive, Negative, or Zero - If/Else & Ternary

Check Sign Using If-Else

#include <stdio.h>
int main() {
    int num;
    printf("Enter an integer: ");
    scanf("%d", &num);
    if (num > 0) {
        printf("%d is positive\n", num);
    } else if (num < 0) {
        printf("%d is negative\n", num);
    } else {
        printf("The number is zero\n");
    }
    return 0;
}

Enter an integer: -7
-7 is negative
        

Practice: Sign with If-Else

This approach compares the input with zero and prints a message depending on whether it is greater, less than or equal to zero.

Check Sign Using Ternary Operator

#include <stdio.h>
int main() {
    int num;
    const char *result;
    printf("Enter an integer: ");
    scanf("%d", &num);
    result = (num > 0) ? "positive" : ((num < 0) ? "negative" : "zero");
    printf("%d is %s\n", num, result);
    return 0;
}

Enter an integer: 0
0 is zero
        

Practice: Sign with Ternary

The ternary operator can compactly choose between multiple expressions. Here it selects one of three strings describing the number based on comparisons with zero.