String Reversal Function: reverseString

Goal: create a function reverseString(str) that returns the input string reversed.

💡 Solution hint:

Possible solutions:

Use split(''), reverse(), join('')
Use a for‑loop iterating backwards
Use recursion (base case: empty string)

Example with array methods:

function reverseString(str) {
  return str.split('').reverse().join('');
}

👀 Peek at solution #1 (Array methods):

/**
 * Reverses a string by changing the order of characters
 * @param {string} str - The input string to reverse
 * @returns {string} The reversed string
 */
function reverseString(str) {
  // 1. Split the string into an array of individual characters
  //    Example: "hello" -> ["h", "e", "l", "l", "o"]
  // 2. Reverse the order of array elements
  //    ["h", "e", "l", "l", "o"] -> ["o", "l", "l", "e", "h"]
  // 3. Join the reversed array back into a string
  //    ["o", "l", "l", "e", "h"] -> "olleh"
  return str.split('').reverse().join('');
}
window.reverseString = reverseString;

Why this way:

Uses built‑in JavaScript methods, short and readable.
Time complexity O(n), space complexity O(n).
Works for any string, including with spaces and Unicode.

👀 Peek at solution #2 (Loop):

function reverseString(str) {
  let reversed = '';
  for (let i = str.length - 1; i >= 0; i--) {
    reversed += str[i];
  }
  return reversed;
}

👀 Peek at solution #3 (Recursion):

function reverseString(str) {
  if (str === '') return '';
  return reverseString(str.slice(1)) + str[0];
}

Task description

Create a function reverseString that takes a string and returns a new string with the characters in reverse order.

How the function should work:

Takes one parameter — a string
Returns a new string with characters in reverse order
Should work correctly with empty strings and palindromes

Usage examples:

reverseString('hello'); // 'olleh'
reverseString('a b'); // 'b a'
reverseString('madam'); // 'madam'

Requirements:

The function must be named reverseString
Accepts one string argument
Returns the string reversed
Must not modify the original string
Must handle Unicode and spaces

Task description

How the function should work:

Usage examples:

Requirements:

String Reversal Function: reverseString

Task description

How the function should work:

Usage examples:

Requirements:

🧑‍💻 It's not a bug! It's a feature!