Write a function that reverses a given string using JavaScript

 You can reverse a string in JavaScript using various methods. Here's a simple function that accomplishes this task using the built-in split(), reverse(), and join() methods:

           
  function reverseString(str) {
  // Split the string into an array of characters
  var characters = str.split('');
  
  // Reverse the array
  var reversedCharacters = characters.reverse();
  
  // Join the characters back into a string
  var reversedString = reversedCharacters.join('');
  
  // Return the reversed string
  return reversedString;
}

// Example usage:
var originalString = "Hello, world!";
var reversedString = reverseString(originalString);
console.log(reversedString); // Output: "!dlrow ,olleH"
           
           
 

Alternatively, you can use a more concise approach by directly chaining the methods:

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

// Example usage:
var originalString = "Hello, world!";
var reversedString = reverseString(originalString);
console.log(reversedString); // Output: "!dlrow ,olleH"