TypeScript函数与类声明

ES6 class了解更多

🔗前往查看

🍒基础使用

constructor为new关键字调用的构造函数

class Speaker {
  name: string                  // 指定属性类型
  constructor (name: string) {
    this.name = name
  }
}

const speaker: Speaker = new Speaker('Jonathan')

🍒继承

📌基础子类

class Say extends Speaker {
  sayHi() {
      console.log(`My name is ${this.name}.`)
  }
}

const say: Say = new Say('Jonathan')   // Say继承了Speaker的属性与方法

📌重写构造函数

class Introduce extends Speaker {
  sex: boolean
  age: number
  constructor (name: string, sex: boolean, age: number) {
    super(name);
    [this.sex, this.age] = [sex, age]
  }
  myIntroduce () {
    console.log(`I am a ${this.age}-year-old ${this.sex? 'boy': 'girl'} `)
  }
}

const introduce: Introduce = new Introduce('Jonathan', true, 20)

🍒修饰符

📌public(默认)

使用public修饰的属性/方法可被子类使用

class Speaker {
  public name: string
  public constructor (name: string) {
    this.name = name
  }
}

const speaker: Speaker = new Speaker('Jonathan')

📌private

class Speaker {
  private name: string
  private constructor (name: string) {
    this.name = name
  }
}

📌protected

s

📌readonly

只读属性应在初始化时赋值(不同于const该属性还可在构造函数内赋值)

class Speaker {
  readonly name: string = 'Jonathan'
  constructor (name: string) {
    this.name = name
  }
}

📌参数属性

给构造函数的参数添加修饰符后参数成为类的属性

class Message {
  constructor (readonly name: string, public age: number, private sex: boolean) {}

  message () {
    console.log(`${this.name} is a ${this.age}-year-old ${this.sex? 'boy': 'girl'}.`)
  }
}

🍒存取器

给类添加get(),与set()接口来修改(读取)属性

class Message {
  constructor (public name: string, public age: number) {}
  
  get () {
    
  }

  set () {
    
  }
}