is that char null terminator is including in the length count

Question

#include <stdio.h>  int main(int argc, char *argv[]) {    char s[]="help";    printf("%d",strlen(s));   } 

Why the above output is 4, isnt that 5 is the correct answer?

it should be 'h','e','l','p','\0' in memory..

Thanks.

Answer 1

strlen: Returns the length of the given byte string not including null terminator;

char s[]="help"; strlen(s) should return 4. 

sizeof: Returns the length of the given byte string, include null terminator;

char s[]="help"; sizeof(s) should return 5. 

Answer 2

strlen counts the elements until it reaches the null character, in which case it will stop counting. It won't include it with the length.