How can I find the length of a particular string in array of pointer to string?

Question

How can I find the length of a string from an array of pointers to a string?

For example, if I want to find the length of the string "apple" then how can I calculate length of it? I tried many ways, but I couldn’t. If I do sizeof(str[0]), it returns the size of the pointer (4 bytes in my 32-bit device). Are they stored in the memory location next to each other or not?

const char *str[] = {
    "apple", "ball", "cat", "dog", "mep", "helsdf"
};

Answer 1

Use strlen() from string.h

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

int main() {
    const char *str[] = {
        "apple", "ball", "cat", "dog", "mep", "helsdf"
    };

    printf("Length of \"%s\": %zu\n", str[0], strlen(str[0]));

    return 0;
}