class?Teammate?{??
??????
???public?final?static?String?name?=?"隊友";//名稱??
??????
????private??int?num?=?5;//數量??
??????
????{??
????	System.out.println("王者榮耀五人黑");??
????}??
??????
	????/**?
?????*?閉包?
?????*?@return?返回一個表示戰斗的匿名內部類?
	?????*/??
????public?Active?BeginFight()??{??
????????return?new?Active(){??
????????????public?void?fight()??
????????????????{??
????????????????if(num?==?0)??
????????????????{??
????????????????????????System.out.println("團滅！");??
????????????????????return;??
????????????????}??
????????????????????num--;??
????????????????System.out.println("隊友陣亡！");??
????????????}??
????????};??
????}??

????public?void?currentNum(){??
	????????System.out.println(name+"剩余："+num);??
????}??
}??
??

interface?Active??{??
????void?fight();??
}??

public?class?Match?{??
??
????public?static?void?main(String[]?args)?{??
????????//來一場比賽?
????????Teammate?t?=?new?Teammate();??
??????????
????????Active?fighting?=?t.BeginFight();??
??????????
????????//激烈戰斗中
????????fighting.fight();??
????????//激烈戰斗中??
????????fighting.fight();??
??????????
????????//看看隊友還在不？??
????????t.currentNum();??
????}??
?
}

java用匿名內部類實現閉包，下面我用JS來實現上面java的代碼！

			function?match(){
			????var?teammates=5;
			????console.log("王者榮耀五人黑");
			????return?function(){
			????	teammates--;
			????	console.log("隊友剩余："+teammates+"！");
			????	if(teammates==0)return?"團滅";
			????????return?teammates;
			????}
			}
			var?fight=match();
			fight();
			fight();

其實閉包就是可以在作用域外使用作用域里的東西，但是會造成內存泄漏因為有另一個引用指向它所以垃圾回收機制不會清理有引用的變量！

很早之前寫過一篇帖子，不知道能不能幫到你?JavaScript 閉包究竟是什么