Length of a String

Given a string s, the task is to find the length of the string.

Examples:

Input: s = "abc"
Output: 3

Input: s = "GeeksforGeeks"
Output: 13

Input: s = ""
Output: 0

Using In-built methods

Every programming language offers a built-in method as well to find the length

// C++ program to find length
// of a string
#include <iostream>
#include <cstring>
using namespace std;

int main()
{
    string s = "gfg";
    cout << s.size() << endl;
    return 0;
}

// C program to find the length of
// string using strlen function
#include <stdio.h>
#include <string.h>

int main()
{
    char s[] = "gfg";
    printf("%ld", strlen(s));
    return 0;
}

/*package whatever //do not write package name here */

import java.io.*;

class GfG {
    public static void main(String[] args)
    {
        String s = "gfg";
        System.out.println(s.length());
    }
}

# Python code to demonstrate string length
# using len

s = "gfg"
print(len(s))

using System;

class GfG
{
    static void Main()
    {
        string s = "gfg";
        Console.WriteLine(s.Length);
        Console.ReadLine();
    }
}

let s = "gfg";
console.log(s.length);

3

Writing your Method

The most traditional method of finding the length of the string is by traversing each character through the loop.

• Using a counter, traverse each character of the string with the help of Loop.
• Return the counter value as the length of the string.

#include <bits/stdc++.h>
using namespace std;

// Method to calculate length of a string
int getLength(const string& s) {
    int i = 0, cnt = 0;
    while (s[i]) {
        i++;
        cnt++;
    }
    return cnt;
}

int main() {
    string s = "GeeksforGeeks";
    cout << getLength(s) << endl;
    return 0;
}

#include <stdio.h>

// Function to calculate length of a string
int getLength(const char* s) {
    int i = 0, cnt = 0;
    while (s[i] != '\0') {
        i++;
        cnt++;
    }
    return cnt;
}

// Driver code
int main() {
    const char* s = "GeeksforGeeks";
    printf("%d\n", getLength(s));

    return 0;
}

public class GfG {

    // Method to calculate length of a string
    static int getLength(String s) {
        int cnt = 0;
        for (char c : s.toCharArray()) {
            cnt++;
        }
        return cnt;
    }

    public static void main(String[] args) {
        String s = "GeeksforGeeks";
        System.out.println(getLength(s));
    }
}

# Function to calculate length of a string
def get_length(s):
    cnt = 0
    for c in s:
        cnt += 1
    
    return cnt

# Driver code
s = "GeeksforGeeks"
print(get_length(s))

using System;

class Program
{
    // Method to calculate length of a string
    static int GetLength(string s)
    {
        int cnt = 0;
        foreach (char c in s)
        {
            cnt++;
        }

        return cnt;
    }

    static void Main()
    {
        string s = "GeeksforGeeks";
        Console.WriteLine(GetLength(s));
    }
}

// Method to calculate length of a string
function getLength(s) {
    let i = 0, cnt = 0;

    // Use a while loop to iterate through 
    // the characters until the end of the string
    while (s[i] !== undefined) {
        i++;
        cnt++;
    }
    
    return cnt;
}

// Driver Code
let s = "GeeksforGeeks";
console.log(getLength(s));

13

Time Complexity: O(n), where n is the length of the string.
Auxiliary space: O(1)