Find the Length of Character Array in C

Last Updated : 23 Jul, 2025

In C, a character array is a collection of elements of the ‘char’ data type that are placed in contiguous memory locations and are often used to store strings. The length of a character array is defined as the total number of characters present in the array, excluding the null character ('\0') at the end. In this article, we will learn how to find the length of a character array in C.

Example:

Input: 
char arr[] = “Hello, Geek!”

Output:
Length of the character array is 12

Finding the Size of a Character Array in C 

To find the length of a character array in C, we can directly use the strlen() function from the <string.h> library. This function returns the length of the character array, excluding the null character.

Syntax to Find Length of Character Array in C

int len = strlen(arr);

Note: The strlen() function even work for arrays passed to functions as it finds the length of the array using the NULL character.

C Program to Find Length of Character Array

The below example demonstrates how we can use the strlen() function to find the the length of character array in C.

C 
// C Program to demonstrate how to find the the length of
// character array
#include <stdio.h>
#include <string.h>

int main()
{
    // Initializing a character array with some elements
    char arr[] = "Hello, Geek!";
    // Finding the length of the character array
    int length = strlen(arr);
    // Printing the length of the character array
    printf("Length of the character array is %d\n", length);

    return 0;
}

Output
Length of the character array is 12

Time Complexity: O(N), where n is the number of characters in the character array.
Auxilliary Space : O(1)


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