Check if two characters are equal in the C language.

In C language, the == operator can be used to determine if two characters are equal. For example:

#include <stdio.h>

int main() {
    char a = 'A';
    char b = 'B';

    if (a == b) {
        printf("a and b are equal.\n");
    } else {
        printf("a and b are not equal.\n");
    }

    return 0;
}

Output:

a and b are not equal.