A preliminary study on JS object-oriented (top) JS Object-oriented 5 methods of writing

For a long time to see the online great God's JS code is particularly difficult, the object-oriented way of writing people to see the clouds in the fog. So the study of JS object-oriented, because it is a beginner, will find themselves on the Internet to collate the information, as a memory.

JS Object -oriented 5 methods of writing: (from http://www.iteye.com/topic/434462)

first define the Circle class, which has member variables R, a constant pi, and a member function area () that calculates the areas;            

The 1th notation  function Circle (r) {        THIS.R = R;  }  Circle.pi = 3.14159;  Circle.prototype.area = function () {    return circle.pi * THIS.R * THIS.R;  }   var c = new Circle (1.0);     Alert (C.area ());   

The 2nd way  var Circle = function () {     var obj = new Object ();     Obj. PI = 3.14159;          Obj.area = function (r) {         return this. PI * R * r;     }     return obj;  }    var c = new Circle ();  Alert (C.area (1.0));  

The 3rd kind of notation  var Circle = new Object ();  Circle.pi = 3.14159;  Circle.area = function (r) {         return this. PI * R * r;  }    Alert (Circle.area (1.0));  

The 4th way  var circle={     "PI": 3.14159,   "area": function (r) {            return). PI * R * r;          }  ;  Alert (Circle.area (1.0));  

The 5th type is  var Circle = new Function ("this"). PI = 3.14159;this.area = function (r) {return r*r*this. PI;} ");    Alert ((New Circle ()). Area (1.0));  

   in the first method to use the Pretotype please see the next section JS in the Pretotype

A preliminary study on JS object-oriented (top) JS Object-oriented 5 methods of writing