前端 TS 快速入门之三：class 类

// ts
class Person {
  // public 默认, 公开的
  public name: string;
  // private 私有属性, 实例和继承不可访问, 本身可以访问
  private age: number;
  // protected 受到保护的, 实例不能访问, 继承和本身可以访问
  protected sex: string;
  // static 静态属性, 只能类本身访问
  static adress: string;
  // readonly 只读, 不能修改
  readonly love: string;
 
  constructor(name: string, age: number, sex: string, love: string) {
    this.name = name;
    this.age = age;
    this.sex = sex;
    this.love = love;
  }
}
 
// js
class Person {
  // static 静态属性, 只能类本身调用
  static age = 18;
  constructor(name) {
    this.name = name;
  }
}

// ts
class Person {
  name: string;
  constructor(name: string) {
    this.name = name;
  }
}
class SuperPerson extends Person {
  age: number;
  constructor(name, age) {
    super(name);
    this.age = age;
  }
}
 
// js
class Person {
  constructor(name) {
    this.name = name;
  }
}
class SuperPerson extends Person {
  constructor(name, age) {
    super(name);
    this.age = age;
  }
}

// ts
class Person {
  name: string;
  constructor(name: string) {
    this.name = name;
  }
  get nameL(): string {
    return `${this.name}.length`;
  }
  set nameL(value: string) {
    this.name = `my newName is ${value}`;
  }
}
 
// js
class Person {
  constructor(name) {
    this.name = name;
  }
 
  get nameL() {
    return this.name.length;
  }
 
  set nameL(value) {
    this.name = `my newName is ${value}`;
  }
}

// ts
abstract class Person {
  name: string;
  constructor(name: string) {
    this.name = name;
  }
  // 抽象方法: 必须被子类实现
  abstract sayHi(): void;
}
class Student extends Person {
  study: string;
  constructor(name: string, study: string) {
    super(name);
    this.study = study;
  }
  sayHi() {
    console.log("hi");
  }
}
 
// js 中没有抽象类