Problem

Given a string, determine if it is a palindrome, considering only alphanumeric characters and ignoring cases.

Note: For the purpose of this problem, we define empty string as valid palindrome.

Example 1:

Input: “A man, a plan, a canal: Panama”

Output: true

Example 2:

Input: “race a car”

Output: false

Pre analysis

Will remove non alphanumberic characters and check palindrome

Post analysis

removal of alphanumeric was better with Regex #todo

Another solution

    var isPalindrome = function(s) {
    s = s.replace(/[^\w]/g,'').toLowerCase();
        let start = 0;
        let end = s.length -1;

        while(start < end){
            if(s[start]!=s[end])
                return false;
            else{
                start++;
                end--;
            }
        }
        return true;
    };