c - Find the size of a string pointed by a pointer

Question

#include <stdio.h>

int main ()
{
    char *ptr = "stackoverflow"

}

Is there any way to find the length of stackoverflow pointed by ptr, as sizeof ptr always gives 4

Answer 1

Use strlen to find the length of (number of characters in) a string

const char *ptr = "stackoverflow";
size_t length = strlen(ptr);

Another minor point, note that ptr is a string literal (a pointer to const memory which cannot be modified). Its better practice to declare it as const to show this.