- This(10分)
1. 例:
function Person (name , age, job) {
this.name = name;
this.age = age;
this.job = job;
}
- 使用new 调用
var person = new Person('lsq',18, 'SE');
this指向?
答:
person
- 直接调用
var person = Person('lsq',18, 'SE');
this指向?
答:
window
- 如何创建作用域安全的构造函数(以题目为例)?
答:
function Person (name , age, job) {
if (this instanceof Person) {
this.name = name;
this.age = age;
this.job = job;
} else {
return new Person(name , age, job);
}
}