* EC(G)
* 變量提升:--
* ----VO(G)
* obj = 0x000
* fn = 0x001
let obj = {
// fn:0x001
fn: (function () {
* EC(AN)
* 作用域鏈:<EC(AN),EC(G)>
* 初始THIS:window
* 形參賦值:--
* 變量提升:--
return function () {
console.log(this);
}; //return 0x001; [[scope]]:EC(AN)
})()
};
obj.fn(); //this->obj
let fn = obj.fn;
fn(); //this->window
var fullName = 'language'; //window.fullName='language'
var obj = { //window.obj=0x000
fullName: 'javascript',
prop: {
getFullName: function () {
return this.fullName;
}
}
};
console.log(obj.prop.getFullName()); //this->obj.prop ->obj.prop.fullName ->undefined
var test = obj.prop.getFullName;
console.log(test()); //this->window ->window.fullName ->'language'
var name = 'window';
var Tom = {
name: "Tom",
show: function () {
// this->window
console.log(this.name); //->'window'
},
wait: function () {
// this->Tom
var fun = this.show; //fun=Tom.show
fun();
}
};
Tom.wait();
window.val = 1; //val是GO的屬性，“也可以說”是全局變量「val=100 / window.val=100」
var json = {
// val是json對象的一個屬性「json.val」
val: 10,
dbl: function () {
this.val *= 2;
}
}
json.dbl();
// this->json
// json.val *= 2 => json.val=json.val*2 => json.val=20
var dbl = json.dbl;
dbl();
// this->window
// window.val *= 2 => window.val=2
json.dbl.call(window);
// this->window 基于call方法強(qiáng)制改變方法中的this是window
// window.val *= 2 => window.val=4
alert(window.val + json.val); //=>“24”
(function () {
// this->window
var val = 1;
var json = {
val: 10,
dbl: function () {
// this->json
// val不是json.val，是其上級上下文中的val變量
val *= 2;
}
};
json.dbl();
alert(json.val + val); //=>“12”
})();
