palindrome without reverse and regex code example

Example 1: palindrome in javascript

function palindrome(str) {

    var len = str.length;
    var mid = Math.floor(len/2);

    for ( var i = 0; i < mid; i++ ) {
        if (str[i] !== str[len - 1 - i]) {
            return false;
        }
    }

    return true;
}

Example 2: how to check palindrome in javascript for lowercase and uppercase

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");