Reverse a String using Recursion

Easy Recursion

Reverse a string using recursion instead of a loop.

Sample input

hello

Sample output

olleh

Solution

def reverse(s):
    if len(s) <= 1:
        return s
    return reverse(s[1:]) + s[0]

print(reverse("hello"))

function reverse(s) {
  if (s.length <= 1) return s;
  return reverse(s.slice(1)) + s[0];
}

console.log(reverse("hello"));

public class Main {
    static String reverse(String s) {
        if (s.length() <= 1) return s;
        return reverse(s.substring(1)) + s.charAt(0);
    }

    public static void main(String[] args) {
        System.out.println(reverse("hello"));
    }
}

fun reverse(s: String): String {
    if (s.length <= 1) return s
    return reverse(s.substring(1)) + s[0]
}

fun main() {
    println(reverse("hello"))
}

func reverse(_ s: String) -> String {
    if s.count <= 1 { return s }
    return reverse(String(s.dropFirst())) + String(s.first!)
}

print(reverse("hello"))

String reverse(String s) {
  if (s.length <= 1) return s;
  return reverse(s.substring(1)) + s[0];
}

void main() {
  print(reverse("hello"));
}

#include <iostream>
#include <string>
using namespace std;

string reverseStr(const string& s) {
    if (s.size() <= 1) return s;
    return reverseStr(s.substr(1)) + s[0];
}

int main() {
    cout << reverseStr("hello") << endl;
    return 0;
}

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

void reverse(const char *s, int index, int len) {
    if (index == len) return;
    reverse(s, index + 1, len);
    putchar(s[index]);
}

int main() {
    char s[] = "hello";
    reverse(s, 0, strlen(s));
    putchar('\n');
    return 0;
}