Recursive string reversal function in javascript?

Question

I\'m a pretty experienced frontend engineer with a weak CS background. I\'m trying to get my head around the concept of recursion. Most of the examples and purported explana

Answer 1

A 25% faster function: jsperf.com

function Reverse(str) {
  if (str === null) {
    return null;
  }
  if (str.length <= 1) {
    return str;
  }
  var first = str[0];
  var last = str[str.length - 1];
  var str1 = Reverse(str.substring(1, str.length - 1));
  return last + str1 + first;
}

var result = Reverse("a really serious string of nothingness making call stack to explode");

Answer 2

So far the best I think:

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

Answer 3

This is a pretty straightforward C# implementation of the algorithm you asked for. I think it could be rewritten in javascript pretty easily.

/*
C#: The Complete Reference 
by Herbert Schildt 

Publisher: Osborne/McGraw-Hill (March 8, 2002)
ISBN: 0072134852
*/


// Display a string in reverse by using recursion. 

using System; 

class RevStr { 

  // Display a string backwards. 
  public void displayRev(string str) { 
    if(str.Length > 0)  
      displayRev(str.Substring(1, str.Length-1)); 
    else  
      return; 

    Console.Write(str[0]); 
  } 
} 

public class RevStrDemo { 
  public static void Main() {   
    string s = "this is a test"; 
    RevStr rsOb = new RevStr(); 

    Console.WriteLine("Original string: " + s); 

    Console.Write("Reversed string: "); 
    rsOb.displayRev(s); 

    Console.WriteLine(); 
  } 
}

Answer 4

Try this:

function recurse(s) {  
  if (s.length == 0) {  
    return '' // stopping condition  
  } else {  // return last char + result of function called with chars up to last char  
    return s.substring(s.length, s.length -1) + recurse(s.substring(0, s.length -1))  
  }
}  

Answer 5

One line of code using ternary operators you can easily reverse it.

Explanation: if string exists (if not null) then return recursion otherwise stop the recursion.

  function reverseString(str) {
    return (str ? reverseString(str.substring(1)) + str.charAt(0) : str);
  }

Function call:

console.log(reverseString('hello'));

Answer 6

function reverse(str) {
  if(str.charAt(0) === ''){
    return "";
  }
  return str.charAt(str.length -1) + reverse(str.substring(0,str.length-1));
}