C Challenge Question

Question

Why it gives no output,
#include <stdio.h>
#include <string.h>
int main() {
char str[10];
char *s = "string";
int length = strlen(*s);
for(int i=0; i<length; i++)
str[i] = s[length - i];
printf ("%s",str);
return 0;
}

Answer 1

It is because you're copying '\0' into str[0]. That means strlen(str) will be 0. In other words, str is empty and there's nothing to print.

int length = strlen(*s); // should be without the * also.

Below is an updated version that reverses the string as you likely want:
#include <stdio.h>
#include <string.h>
int main() {
char str[10];
char *s = "string";
int length = strlen(s);

str[length] = '\0'; // mark end of string.
for(int i=0; i<length; i++)
str[i] = s[length - i - 1];
printf ("%s",str);
return 0;
}

Answer 2

Thank you.