// 对象字面量
var Singleton = {
  attr1: 1,
  attr2: 2,
  method1: function(){
    return this.attr1;
  },
  method2: function(){
    return this.attr2;
  }
};

// 单体模式
var Singleton = function(name){
  this.name = name;
  this.instance = null;
};
Singleton.prototype.getName = function(){
  return this.name;
}
// 获取实例对象
function getInstance(name) {
  if(!this.instance) {
    this.instance = new Singleton(name);
  }
  return this.instance;
}
// 测试单体模式的实例
var a = getInstance("aa");
var b = getInstance("bb");

// 因为单体模式是只实例化一次，所以下面的实例是相等的
console.log(a === b); // true

console.log(a.getName());// aa
console.log(b.getName());// aa

// 单体模式
var Singleton = function(name){
  this.name = name;
};
Singleton.prototype.getName = function(){
  return this.name;
}
// 获取实例对象
var getInstance = (function() {
  var instance = null;
  return function(name) {
    if(!instance) {
      instance = new Singleton(name);
    }
    return instance;
  }
})();
// 测试单体模式的实例
var a = getInstance("aa");
var b = getInstance("bb");
// 因为单体模式是只实例化一次，所以下面的实例是相等的

console.log(a === b); // true

console.log(a.getName());// aa

console.log(b.getName());// aa

// 单体模式
var CreateDiv = function(html) {
  this.html = html;
  this.init();
}
CreateDiv.prototype.init = function(){
  var div = document.createElement("div");
  div.innerHTML = this.html;
  document.body.appendChild(div);
};
// 代理实现单体模式
var ProxyMode = (function(){
  var instance;
  return function(html) {
    if(!instance) {
      instance = new CreateDiv("我来测试下");
    }
    return instance;
  } 
})();
var a = new ProxyMode("aaa");
var b = new ProxyMode("bbb");
console.log(a===b);// true

// 实现弹窗
var createWindow = function(){
  var div = document.createElement("div");
  div.innerHTML = "我是弹窗内容";
  div.style.display = 'none';
  document.body.appendChild('div');
  return div;
};
document.getElementById("Id").onclick = function(){
  // 点击后先创建一个div元素
  var win = createWindow();
  win.style.display = "block";
}

// 实现单体模式弹窗
var createWindow = (function(){
  var div;
  return function(){
    if(!div) {
      div = document.createElement("div");
      div.innerHTML = "我是弹窗内容";
      div.style.display = 'none';
      document.body.appendChild(div);
    }
    return div;
  }
})();
document.getElementById("Id").onclick = function(){
  // 点击后先创建一个div元素
  var win = createWindow();
  win.style.display = "block";
}

var createIframe = (function(){
  var iframe;
  return function(){
    if(!iframe) {
      iframe = document.createElement("iframe");
      iframe.style.display = 'none';
      document.body.appendChild(iframe);
    }
    return iframe;
  };
})();

var getInstance = function(fn) {
  var result;
  return function(){
    return result || (result = fn.call(this,arguments));
  }
};

// 创建div
var createWindow = function(){
  var div = document.createElement("div");
  div.innerHTML = "我是弹窗内容";
  div.style.display = 'none';
  document.body.appendChild(div);
  return div;
};
// 创建iframe
var createIframe = function(){
  var iframe = document.createElement("iframe");
  document.body.appendChild(iframe);
  return iframe;
};
// 获取实例的封装代码
var getInstance = function(fn) {
  var result;
  return function(){
    return result || (result = fn.call(this,arguments));
  }
};
// 测试创建div
var createSingleDiv = getInstance(createWindow);
document.getElementById("Id").onclick = function(){
  var win = createSingleDiv();
  win.style.display = "block";
};
// 测试创建iframe
var createSingleIframe = getInstance(createIframe);
document.getElementById("Id").onclick = function(){
  var win = createSingleIframe();
  win.src = "http://www.jb51.com";
};