[Refactor] avoid using a sparse array.

Author: ljharb

lib/utils.js

@@ -1,9 +1,9 @@
 'use strict';
 
 var hexTable = (function () {
-    var array = new Array(256);
+    var array = [];
     for (var i = 0; i < 256; ++i) {
-        array[i] = '%' + ((i < 16 ? '0' : '') + i.toString(16)).toUpperCase();
+        array.push('%' + ((i < 16 ? '0' : '') + i.toString(16)).toUpperCase());
     }
 
     return array;