JavaScript palindrome number

Basic Solutions

function palindrome (str) {  return str.replace (/[\w_]/g, "). toLowerCase () = = =         str.replace ( /[\w_]/g, "). toLowerCase (). Split ("). Reverse (). Join (');}

Intermediate Code Solution

function palindrome (str) {  = str.tolowercase (). Replace (/[\w_]/g, ");    for (var i = 0, len = str.length-1; i < LEN/2; i++) {    if(Str[i]!== str[len-i]) {      returnfalse;    }  }   returntrue;}

Advanced Code Solutions (highest performance)

functionpalindrome (str) {Let front = 0; Let's back= Str.length-1; //Back and front pointers won ' t all meet in the middle, so use (Back > Front)   while(Back >front) {    //increments front pointer if current character doesn ' t meet criteria     while(Str[front].match (/[\w_]/) ) {Front++; Continue; }    //decrements back pointer if current character doesn ' t meet criteria     while(Str[back].match (/[\w_]/) { back--; Continue; }    //finally does the comparison on the current character    if(Str[front].tolowercase ()!== str[back].tolowercase ())return falseFront++; back--; }    //if the whole string has been compared without returning false, it's a palindrome!  return true;}

JavaScript palindrome number