function person (){
this.age = 10;
this.name = "Kevin";
};
var p = new person();
console.log(p.age + ":" + p.name);
function person_closure (age, name) {
this.getName = function () {return name; };
this.setName = function (newName) {name = newName; };
this.getAge = function () {return age;};
this.setAge = function (newAge) {age = newAge;};
}
var p_c = new person_closure(10, "Kevin");
console.log(p_c.age + ":" + p_c.name);
console.log(p_c);
p_c = null;Check out this Pen!
競選總部決定，網站必須改版，盡一切可能爭取捐款。於是，技術團隊開始大規模的擴充，全職的前端工程師從1個人擴充到了14個人，其中6人專門負責製作募款頁面。
| 出現情況 | this 說明 | 範例程式 |
| 物件方法的呼叫 | 呼叫方法的物件 (Caller) |
var obj = new Object(); obj.id = "test"; obj.findThis = function(){ alert(this.id)}; obj.findThis(); // this is obj. |
| Global Function 呼叫 | window, strict mode is undefined. Caller is window |
function test(){ alert(this); } test(); |
| 使用 new產生一個 instance | 就是 這個物件本身 | function test(){ alert(this) } var o = new test(); //this is o |
| 使用
Apply, Call呼叫函數 帶入第一個參數值改變 Context. |
被改變的 Context值 | function test(){ alert(this.id); } var m = {id: "m"}; var n = {id: "n"}; var o = {id: "o"}; o.fn = test; o.fn.apply(m); // this is m o.fn.call(n); // this is n |
var arg = 1;
function funcTest() {
alert(arg);
var arg = 2;
}
funcTest();
function funcTest2() {
alert(arg);
//var arg = 2;
}
funcTest2();
Check out this Pen!