1. 类的定义和使用
class Student {
name;
say() {
console.log(this.name + " saying");
}
}
var s1 = new Student();
s1.name = "zhangsan";
s1.say();
var s2 = new Student();
s2.name = "lisi";
s2.say();
2. 类的构造函数
class Student {
constructor(name: string) {
this.name = name;
}
name;
say() {
console.log(this.name + " saying");
}
}
var s1 = new Student("zhangsan");
s1.say();
var s2 = new Student("lisi");
s2.say();
类的构造函数定义在constructor
效果图
上面的代码可以简写为
class Student {
constructor(public name: string) {
}
say() {
console.log(this.name + " saying");
}
}
var s1 = new Student("zhangsan");
s1.say();
var s2 = new Student("lisi");
s2.say();
输出结果是一样的
3. 类的继承
class Student {
constructor(public name: string) {
}
say() {
console.log(this.name + " saying");
}
}
class HighSchoolStudent extends Student {
constructor(name: string, no: string) {
super(name)
}
no:string;
study() {
super.say();
}
}
var hStudent = new HighSchoolStudent("wangwu","06169020");
hStudent.say();
extends 代表要继承的类
super(name)调用父类的构造函数
super.say(); 调用父类的方法