Added constructor pattern examples

Author: ryankinal

constructor.js

@@ -0,0 +1,46 @@
+/*
+    Examples from The Illusion of Class by Ryan Kinal
+
+    http://blog.javascriptroom.com/2013/01/29/the-illusion-of-class/
+*/
+
+// Construcors are just functions
+var Point = function(x, y)
+{
+    this.x = x;
+    this.y = y;
+}
+
+// Put "methods" on the prototype property of the function
+Point.prototype.translate = function(x, y)
+{
+    this.x += x;
+    this.y += y;
+}
+ 
+// Use the "new" keyword to create a new object
+// with a prototype equal to Point.prototype
+var point = new Point(17, 42);
+point.translate(5, 6);
+
+/*
+    I loves me some inheritance!
+*/
+var Point3d = function(x, y, z)
+{
+    Point.call(this, x, y);
+    this.z = z;
+}
+ 
+Point3d.prototype = new Point();
+// OR
+Point3d.prototype = Object.create(Point.prototype); // probably better
+ 
+Point3d.prototype.translate = function(x, y, z)
+{
+    Point.prototype.translate.call(this, x, y);
+    this.z += z;
+}
+ 
+var point3d = new Point3d(19, 20, 21);
+point3d.translate(4, 5, 6);