JavaScript中的6种对象构建模式

参考:
- JavaScript高级程序设计(第2版)
- http://www.ruanyifeng.com/blog/2012/07/three_ways_to_define_a_javascript_class.html

• 即时量模式

var Obj = new Object;
Obj.name = 'sun';
Obj.showName = function() {
    alert('this.name');
}

• 工厂模式

function createObj(name) {
    var tempObj = new Object;
    tempObj.name = name;
    tempObj.showName = function () {
        alert(this.name);
    };
    return tempObj;
}
var obj1 = createObj('obj_one');
var obj2 = createObj('obj_two');

• 工厂模式改进版

function showName () {
    alert(this.name);
}    
function createObj(name) {
    var tempObj = new Object;
    tempObj.name = name;
    tempObj.showName = showName;
    return tempObj;
}
var obj1 = createObj('obj_one');
var obj2 = createObj('obj_two');

• 构造函数模式

function Obj(name) {
    this.name = name;
    this.showName = function () {
        alert(this.name);
    }
}
var obj1 = new Obj('obj_one');
var obj2 = new Obj('obj_two');

• 原型模式

var Obj = function () {}
Obj.prototype.name = 'me';
Obj.prototype.flag = new Array('A', 'B');
Obj.prototype.showName = function () {
    alert(this.name);
}
var obj1 = new Obj();
var obj2 = new Obj();
obj1.flag.push('C');
alert(obj1.flag); // A,B,C
alert(obj2.flag); //A,B,C

• 构建函数+原型模式

var Obj = function (name) {
    this.name = name;
    this.flag = new Array('A', 'B');
}
Obj.prototype = {
    showName : function () {
        alert(this.name);
    }
}
var obj1 = new Obj();
var obj2 = new Obj();
obj1.flag.push('C');
alert(obj1.flag); // A,B,C
alert(obj2.flag); //A,B

• 构建函数+原型模式完美版

var Obj = function (name) {
    this.name = name;
    this.flag = new Array('A', 'B');
    if (typeof Obj._init == 'undefined') {
        Obj.prototype = {
            showName : function () {
                alert(this.name);
            }
        };
        Obj._init = true;
    }
}