爲什麼this.age = age;
與age = this.age
不同。第二個是未定義的。在以下代碼中爲javascript添加新屬性(此)關鍵字
代碼:
function person(firstname,lastname,age,eyecolor) {
this.firstname = firstname;
this.lastname = lastname;
//this.age = age;
age = this.age;
this.eyecolor = eyecolor;
this.changeName = changeName;
function changeName(name) {
// this.lastname = name;
name = this.lastname;
}
}
var myMother = new person("Sally","Rally",48,"green");
myMother.changeName("Doe");
document.getElementById("demo").innerHTML =
"My mother's last name is " + myMother.lastname;
如果我們改變的變化不會發生的順序name = this.lastname
。
因爲'this'沒有屬性'age',你需要在設置它之前設置它。 – levi 2014-08-29 21:08:06
你的問題是什麼?你爲什麼期望兩種不同的事情做同樣的事情? – 2014-08-29 21:08:22
@levi「this.lastname」呢? – arash 2014-08-29 21:12:21