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<title>Document</title>
<script>
//场景1
//当定义的函数，没有被上级所调用，那么这个this代表window
var test = function(){
var name = 'liu';
console.log(this); //windows 对象
alert(this.name); //空
}
test();
//场景2 此处this 为 test1，可以直接访问对象属性
console.log(typeof([])); //type类型为object
consoel.log(typeof({})) // type类型为object
var test1 = {
name: "liu",
fn: function(){
console.log(this.name); //liu
}
}
test1.fn();
//场景3 调用执行方法的对象为obj，所以这里this就是obj，自然可以访问到name，结果为obj.name
//如果上层有多个层级对象，则this为离他最近的调用对象
var test2 = {
name: "liu",
obj:{
name: "obj.liu",
fn: function(){
console.log(this.name); //obj.liu
}
}
}
test2.obj.fn();
</script>
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