Two Ways to Check for Palindromes in JavaScript

1. Check for Palindromes With Built-In Functions

function palindrome(str) {
  var re = /[\W_]/g;
  var lowRegStr = str.toLowerCase().replace(re, '');
  var reverseStr = lowRegStr.split('').reverse().join(''); 
  return reverseStr === lowRegStr;
}
palindrome("A man, a plan, a canal. Panama");

2. Check for Palindromes With a FOR loop

function palindrome(str) {
 var re = /[^A-Za-z0-9]/g;
 str = str.toLowerCase().replace(re, '');
 var len = str.length;
 for (var i = 0; i < len/2; i++) {
   if (str[i] !== str[len - 1 - i]) {
       return false;
   }
 }
 return true;
}
palindrome("A man, a plan, a canal. Panama");

3. Check For Palindrome With Iteration

function isPalindrome(word) {
    let left = 0
    let right = word.length-1

    while (left < right) {
        if (word[left] !== word[right]) return false
        left++
        right--
    }
    
    return true
}

isPalindrome("neuquen") // true
isPalindrome("Buenos Aires") // false