Library Functions - General Questions

Which function converts a string to a double?

What will be the output of the program?

#include <stdio.h>
#include <math.h>

int main(void) {
    printf("%.0f\n", fabs(-12.0));
    return 0;
}

What will be the output of the program?

#include <stdio.h>
#include <string.h>

int main(void) {
    char s[] = "hello world";
    printf("%s\n", strchr(s, 'w'));
    return 0;
}

What will be the output of the program?

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

int main(void) {
    printf("%d\n", isdigit('7') != 0);
    return 0;
}

What will be the output of the program?

#include <stdio.h>
#include <math.h>

int main(void) {
    printf("%.1f\n", sqrt(49.0));
    return 0;
}