updated palindrome to be slightly more efficient

Author: bethrobson

chapter13/palindrome.html

@@ -7,13 +7,10 @@
 
 String.prototype.palindrome = function() {
 	var len = this.length-1;
-	for (var i = 0; i <= len; i++) {
+	for (var i = 0; i <= len/2; i++) {
 		if (this.charAt(i) !== this.charAt(len-i)) {
 			return false;
 		}
-		if (i === (len-i)) {
-			return true;
-		}
 	}
 	return true;
 };