Print reverse of a string using recursion

Write a recursive function to print reverse of a given string.

Program:

C++

// C++ program to reverse a string using recursion  
#include <bits/stdc++.h> 
using namespace std; 
  
/* Function to print reverse of the passed string */
void reverse(string str)  
{  
    if(str.size() == 0) 
    { 
        return; 
    } 
    reverse(str.substr(1)); 
    cout << str[0]; 
}  
  
/* Driver program to test above function */
int main()  
{  
    string a = "Geeks for Geeks";  
    reverse(a);  
    return 0;  
}  
  
// This is code is contributed by rathbhupendra 

C

// C program to reverse a string using recursion 
# include <stdio.h> 
  
/* Function to print reverse of the passed string */
void reverse(char *str) 
{ 
   if (*str) 
   { 
       reverse(str+1); 
       printf("%c", *str); 
   } 
} 
  
/* Driver program to test above function */
int main() 
{ 
   char a[] = "Geeks for Geeks"; 
   reverse(a); 
   return 0; 
} 

Java

// Java program to reverse a string using recursion 
  
class StringReverse 
{ 
    /* Function to print reverse of the passed string */
    void reverse(String str) 
    { 
        if ((str==null)||(str.length() <= 1)) 
           System.out.println(str); 
        else
        { 
            System.out.print(str.charAt(str.length()-1)); 
            reverse(str.substring(0,str.length()-1)); 
        } 
    } 
      
    /* Driver program to test above function */
    public static void main(String[] args)  
    { 
        String str = "Geeks for Geeks"; 
        StringReverse obj = new StringReverse(); 
        obj.reverse(str); 
    }     
} 

Python

# Python program to reverse a string using recursion 
  
# Function to print reverse of the passed string 
def reverse(string): 
    if len(string) == 0: 
        return
      
    temp = string[0] 
    reverse(string[1:]) 
    print(temp, end='') 
  
# Driver program to test above function 
string = "Geeks for Geeks"
reverse(string) 
  
# A single line statement to reverse string in python 
# string[::-1] 
  
# This code is contributed by Bhavya Jain 

C#

// C# program to reverse  
// a string using recursion 
using System; 
  
class GFG 
{ 
    // Function to print reverse 
    // of the passed string 
    static void reverse(String str) 
    { 
        if ((str == null) || (str.Length <= 1)) 
        Console.Write(str); 
      
        else
        { 
            Console.Write(str[str.Length-1]); 
            reverse(str.Substring(0,(str.Length-1))); 
        } 
    } 
      
    // Driver Code 
    public static void Main()  
    { 
        String str = "Geeks for Geeks"; 
        reverse(str); 
    }  
} 
  
// This code is contributed by Sam007 

PHP

<?php 
// PHP program to reverse  
// a string using recursion 
  
// Function to print reverse 
// of the passed string 
function reverse($str) 
{ 
    if (($str == null) ||  
        (strlen($str) <= 1)) 
    echo ($str); 
  
    else
    { 
        echo ($str[strlen($str) - 1]); 
        reverse(substr($str, 0,  
               (strlen($str) - 1))); 
    } 
} 
  
// Driver Code 
$str = "Geeks for Geeks"; 
reverse($str); 
  
// This code is contributed by  
// Manish Shaw(manishshaw1) 
?> 

Output:

skeeG rof skeeG

Explanation: Recursive function (reverse) takes string pointer (str) as input and calls itself with next location to passed pointer (str+1). Recursion continues this way, when pointer reaches ‘\0’, all functions accumulated in stack print char at passed location (str) and return one by one.

Time Complexity: O(n)

See Reverse a string for other methods to reverse string.

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

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My Personal Notes

C++

C

Java

Python

C#

PHP

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