<script type="text/javascript"> 
 //function(){}//會(huì)報(bào)錯(cuò) 
 var fun = function(){};//將匿名函數(shù)賦值給變量 
 
 (function(){})();//匿名函數(shù)自執(zhí)行 
 
 function(){ 
 return function(){};//函數(shù)里的匿名函數(shù) 
 } 
</script> 

<script type="text/javascript"> 
 //通過(guò)閉包可以返回局部變量 
 function box() { 
 var user = 'Lee'; 
 return function () { //通過(guò)匿名函數(shù)返回box()局部變量 
  return user; 
 }; 
 } 
 console.log(box()());  //通過(guò)box()()來(lái)直接調(diào)用匿名函數(shù)返回值 
 var b = box(); 
 console.log(b());  //另一種調(diào)用匿名函數(shù)返回值 
 
 //通過(guò)閉包可以實(shí)現(xiàn)局部變量的累加 
 function box() { 
 var age = 100; 
 return function () { 
  age ++; 
  return age; 
 } 
 } 
 var b = box();  //獲得函數(shù) 
 console.log(b());  //調(diào)用匿名函數(shù) 
 console.log(b());  //第二次調(diào)用匿名函數(shù)，實(shí)現(xiàn)累加 
</script> 

<script type="text/javascript"> 
 function box() { 
 var arr = []; 
 
 for (var i = 0; i < 5; i++) { 
  arr[i] = function () { 
  return i; 
  }; 
 } 
 return arr; 
 } 
 
 var b = box();    //得到函數(shù)數(shù)組 
 console.log(b.length);   //得到函數(shù)集合長(zhǎng)度 
 for (var i = 0; i < b.length; i++) { 
 console.log(b[i]());   //輸出每個(gè)函數(shù)的值，都是最后一個(gè)值 
 } 
</script> 

<script type="text/javascript"> 
 function box() { 
 var arr = []; 
 
 for (var i = 0; i < 5; i++) { 
  arr[i] = (function (num) { 
  return function () {  //返回函數(shù) 
   return num; 
  } 
  })(i); 
  /* 
  //相當(dāng)于: 
  arr[i] = (function () { 
  var num = i;//定義一個(gè)局部變量 
  return function () { 
   return num; 
  } 
  })(); 
  */ 
 } 
 return arr; 
 } 
 
 var b = box();    //得到函數(shù)數(shù)組 
 for (var i = 0; i < b.length; i++) { 
 console.log(b[i]());   //0,1,2,3,4 
 } 
</script> 

<script type="text/javascript"> 
 var user = 'The Window'; 
 
 var obj = { 
 user : 'The Object', 
 getUserFunction : function () { 
  return function () { //閉包不屬于obj，里面的this指向window 
  return this.user; 
  }; 
 } 
 }; 
 console.log(obj.getUserFunction()()); //The window 
 //可以強(qiáng)制指向某個(gè)對(duì)象 
 console.log(obj.getUserFunction().call(obj)); //The Object 
 /* 
 //也可以從上一個(gè)作用域中得到對(duì)象 
 getUserFunction : function () { 
 var that = this;  //從對(duì)象的方法里得對(duì)象 
 return function () { 
  return that.user; 
 }; 
 } 
 */ 
</script> 

<script type="text/javascript"> 
 //使用塊級(jí)作用域(私有作用域)改寫 
 function box(count) { 
 (function () { 
  for (var i = 0; i<count; i++) {} 
 })(); 
 console.log(i); //報(bào)錯(cuò)，無(wú)法訪問(wèn) 
 } 
 box(2); 
</script> 

<script type="text/javascript"> 
 function Box() { 
 var age = 100;   //私有變量 
 function run() {   //私有函數(shù) 
  return '運(yùn)行中...'; 
 } 
 this.get = function () {  //對(duì)外公共的特權(quán)方法,閉包（函數(shù)訪問(wèn)了不屬于對(duì)象作用域的age和run方法） 
  return age + run(); 
 }; 
 } 
 
 var box = new Box(); 
 console.log(box.get()); 
</script> 

<script type="text/javascript"> 
 (function () { 
 var age = 100;//靜態(tài)私有變量 
 function run() { 
 return '運(yùn)行中...'; 
 } 
 Box = function () {}; //構(gòu)造方法，沒(méi)有使用var，全局函數(shù) 
 Box.prototype.go = function () { //原型方法 
 return age + run(); 
 }; 
 })(); 
 
 var box = new Box(); 
 console.log(box.go()); 
</script> 

<script type="text/javascript"> 
 var box = function () { //box是一個(gè)模塊 
 var age = 100; 
 function run() { 
 return '運(yùn)行中...'; 
 } 
 return { //直接返回對(duì)象 
 go : function () { 
 return age + run(); 
 } 
 }; 
 }(); 
</script>