<html>
<head>
</head>
<body>
</body>
<script>
var x=20;
var a={
x:15,
fn: function(){
var x=30;
return function(){
return this.x;
}
}
}
console.log(a.fn());
console.log((a.fn())());
console.log(a.fn()());
console.log(a.fn()()==(a.fn())());
console.log(a.fn().call(this));
console.log(a.fn().call(a));
</script>
</html>
输出结果: