How to Convert a String to a Char Array in C?

In C, the only difference between the string and a character array is possibly the null character '\0' but strings can also be declared as character pointer in which case, its characters are immutable. In this article, we will learn how to convert a string to a char array in C.

The most straightforward method to convert a string to a char array is by using strcpy() function. Let's take a look at an example:

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

int main() {
    char *s = "Hello";
    char arr[20];     

    // Convert the string to a char array
    strcpy(arr, s);

    printf("%s", arr); 
    return 0;
}

Hello

Explanation: The strcpy() function, copies the contents of a source string into a destination character array. This function automatically handles the copying of characters, including the null terminator ('\0'), ensuring the string is properly converted into a char array.

There are also one other methods in C to convert a string to a char array.

Manually Using Loop

Instead of using built-in functions, each character from the string can be manually copied into a character array using a loop including the null character.

#include <stdio.h>

void convert(char *s, char *arr) {
    while (*arr++ = *s++);
}

int main() {
    char s[] = "Hello";  
    char arr[20];

    // Convert the string to a char array
    convert(s, arr);

    printf("%s", arr);
    return 0;
}

Hello