// 定義一個(gè)類
function Singleton(name) {
this.name = name;
this.instance = null;
}
// 原型擴(kuò)展類的一個(gè)方法getName()
Singleton.prototype.getName = function() {
console.log(this.name)
};
// 獲取類的實(shí)例
Singleton.getInstance = function(name) {
if(!this.instance) {
this.instance = new Singleton(name);
console.log(this.instance) // {name: 'a', instance: null}
}
return this.instance
};
// 獲取對(duì)象1
var a = Singleton.getInstance('a');
// 獲取對(duì)象2
var b = Singleton.getInstance('b');
// 進(jìn)行比較
console.log(a === b); // true

// 單例構(gòu)造函數(shù)
function CreateSingleton (name) {
this.name = name;
this.getName();
};
// 獲取實(shí)例的名字
CreateSingleton.prototype.getName = function() {
console.log(this.name)
};
// 單例對(duì)象
var Singleton = (function(){
var instance;
return function (name) {
if(!instance) {
instance = new CreateSingleton(name);
}
return instance;
}
})();
// 創(chuàng)建實(shí)例對(duì)象1
var a = new Singleton('a');
// 創(chuàng)建實(shí)例對(duì)象2
var b = new Singleton('b');
console.log(a===b);