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);
}