Valid Palindrome
Description
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.
Solution(javascript)
/**
* @param {string} s
* @return {boolean}
*/
var isPalindrome = function(s) {
let str = s.replace(/[^A-Za-z0-9]/g, '').toLowerCase();
if (str == str.split("").reverse().join("")) {
return true;
} else {
return false;
}
};