Palindrome in JavaScript

A palindrome is a word, phrase, number, or other sequence of characters that reads the same forward and backward. In JavaScript, you can check if a string is a palindrome using various approaches. Here’s one way to check for a palindrome in JavaScript:

function isPalindrome(str) {
  // Remove non-alphanumeric characters and convert to lowercase
  var cleanedStr = str.toLowerCase().replace(/[^a-zA-Z0-9]+/g, '');

  // Reverse the string
  var reversedStr = cleanedStr.split('').reverse().join('');

  // Compare the original and reversed strings
  return cleanedStr === reversedStr;
}

// Test the function
console.log(isPalindrome("level")); // true
console.log(isPalindrome("Hello")); // false
console.log(isPalindrome("A man, a plan, a canal: Panama")); // true
console.log(isPalindrome("12321")); // true
console.log(isPalindrome("12345")); // false

In this code, the isPalindrome function takes a string (str) as input and performs the following steps:

1. It cleans the string by converting it to lowercase and removing any non-alphanumeric characters using a regular expression.
2. It reverses the cleaned string by splitting it into an array of characters, reversing the array, and joining the characters back together.
3. It compares the cleaned string with the reversed string and returns true if they are equal, indicating that the original string is a palindrome. Otherwise, it returns false.

You can test this function with different strings to see if they are palindromes.