JavaScript中的私有属性

一、使用构造函数获得私有属性：

function Gadget(){
    var name = 'iPod';
    this.getName = function(){
        return name;
    };
};

var toy = new Gadget();
console.log(toy.name);//undefined
console.log(toy.getName());//iPod

注意，当返回变量为数组或对象时，私有性失效：

function Gadget(){
    var specs = {
         400,
        height: 500
    };
    this.getSpecs = function(){
        return specs;
    };
};

var toy = new Gadget();
var specs = toy.getSpecs();
specs.color = 'black';
console.log(toy.getSpecs());//{  400, height: 500, color: 'black' }

二、使用对象字面量

var myobj = (function(){
    var name = 'wqh';
    return {
        getName: function(){
            return name;
        }
    }
})();
console.log(myobj.name);//undefined
console.log(myobj.getName());//wqh

三、共享的私有属性：prototype中

function Gadget(){
    var name = 'iPod';
    this.getName = function(){
        return name;
    };
};

Gadget.prototype = (function(){
    var browser = 'Webkit';
    return {
        getBrowser: function(){
            return browser;
        }
    };
})();

var toy = new Gadget();

console.log(toy.name);//undefined
console.log(toy.getName());//iPod
console.log(toy.browser);//undefined
console.log(toy.getBrowser());//Webkit

注：JavaScript模式P94-98