闭包小demo

var a = (function(){

		var c= 0;

		return function(){

				return ++c;
		}

	}());

	var g = a();
	console.log(g);
	var e= a();
	console.log(e);
	var f = a();
	console.log(f);//变量c不清零

通过闭包打印出li有几个节点

<ul id="test">
	<li>1
	<li>2
	<li>3
	<li>4
</ul>

var test = document.getElementById("test"),
		li = test.getElementsByTagName("li");

	for(var i=0,len = li.length;i<len;i++){

		li[i].onclick = function(num){

				return function(){

					console.log(++num);

				}

		}(i);

	}