Palindrome1

Author: highflyer910

palindrome1.js

@@ -1,12 +1,5 @@
-function isPalindrome(string) {
-  string = string.toLowerCase();
-  var charactersArr = string.split('');
-  var validCharacters = 'abcdefghijklmnopqrstuvwxyz'.split('');
-  
-  var lettersArr = [];
-  charactersArr.forEach(char => {
-    if (validCharacters.indexOf(char) > -1) lettersArr.push(char);
-  });
-  
-  return lettersArr.join('') === lettersArr.reverse().join('');
+function palindrome(str) {
+  var normalizedStr = str.replace(/[\W_]/g, '').toLowerCase();
+  var reverseStr = normalizedStr.split('').reverse().join('');
+  return normalizedStr === reverseStr;
 }