validPalindrome.js

//////////////////////////////////////////////Valid Palindrome/////////////////////////////////////////////////
// A phrase is a palindrome if, after converting all uppercase letters into lowercase letters and removing all non-alphanumeric
// characters, it reads the same forward and backward. Alphanumeric characters include letters and numbers.
// Given a string s, return true if it is a palindrome, or false otherwise.
// Example 1:
// Input: s = "A man, a plan, a canal: Panama"
// Output: true
// Explanation: "amanaplanacanalpanama" is a palindrome.
// Example 2:
//
// Input: s = "race a car"
// Output: false
// Explanation: "raceacar" is not a palindrome.
// Example 3:
//
// Input: s = " "
// Output: true
// Explanation: s is an empty string "" after removing non-alphanumeric characters.
// Since an empty string reads the same forward and backward, it is a palindrome.
// Constraints:
// 1 <= s.length <= 2 * 105
// s consists only of printable ASCII characters.
const isPalindrome2 = function(s) {
    let str = s.toLowerCase().replace(/[^a-z 0-9]/g, "").split(' ').join('');
    let revStr = str.split('').reverse().join('');

    return str === revStr ? true : false;
};


// console.log(isPalindrome2("A man, a plan, a canal: Panama"));
// console.log(isPalindrome2("race a car"));
// console.log(isPalindrome2("0P"));