palindrome 5 6 1 5 1 6 output 1 in javascript code example

Example 1: javascript palindrome check

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");

Example 2: javascript palindrome

function remove_spaces_strict(string)
{
    return string.replace(/\s/gm, "");
}

function to_lower_case(string="")
{
    return string.toLocaleLowerCase();
}


function isPalindrome(string) {
    let string1 = string;
    if (typeof string === 'string' || typeof string === 'number') {
        if (typeof string === 'number') {
            string1 = new Number(string1).toString();
        }
        string1 = remove_spaces_strict(string1);
        string1 = to_lower_case(string1);
        let len1 = string1.length;
        let len = Math.floor(string1.length / 2);
        let i = 0;

        while(i < len) {
    
                if (string1[i] !== string1[len1 - (1 + i)]) {
                    return false;
                }
                console.log(string1[i] + " = " + string1[len1 - (1 + i)]);
                i++;
            }
    }else{
        throw TypeError(`Was expecting an argument of type string1 or number, recieved an argument of type ${ typeof string1}`);
    }
    return string;
}