类-1

1. 类的基本使用

export default {};

class Person {
  name: string;
  age: number;

  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }

  sayHello(): void {
    console.log(
      `我的女神是${this.name},她今年${this.age}岁了,但是在我的心里,她永远18岁`
    );
  }
}

let p = new Person("邱淑贞", 54);
p.sayHello();

2. 类的继承

export default {};

class Person {
  name: string;
  age: number;

  constructor(name: string, age: number) {
    this.name = name;
    this.age = age;
  }

  say(): void {
    console.log(`我是${this.name}, 今年${this.age}岁了`);
  }
}

// 需求: 在子类也想要父类的方法.怎么办?

class Student extends Person {
  score: string;

  constructor(name: string, age: number, score: string) {
    super(name, age);
    this.score = score;
  }

  say(): void {
    super.say();
    console.log(
      `我是重写之后的say方法, 我是学生${this.name}, 今年${this.age}岁了,我的成绩为${this.score}`
    );
  }
}

let s = new Student("蒋依依", 18, "A");
s.say();

3. static 与 Instanceof

export default {};

// static
class StaticTest {
  static salary: string;
  static say(): void {
    console.log("我们想要的工资是: " + this.salary);
  }
}

StaticTest.salary = "18k";
StaticTest.say();

// instanceof
class Person {}
let p = new Person();
let isPerson = p instanceof Person;
console.log("p对象是Person类实例化来的嘛？" + isPerson);

class Student extends Person {}
let s = new Student();
let isPerson2 = s instanceof Person;
console.log("p对象是Person类实例化来的嘛？" + isPerson2);

4. 类中的修饰符

export default {};

class Person {
  public name: string;
  protected age: number;
  private sex: string;

  constructor(name: string, age: number, sex: string) {
    this.name = name;
    this.age = age;
    this.sex = sex;
  }

  say(): void {
    console.log(
      `我的名字是${this.name}, 性别为${this.sex}, 今年${this.age}岁了`
    );
  }
}

let p = new Person("邱淑贞", 18, "女");
p.say();

class Student extends Person {
  score: string;
  constructor(name: string, age: number, sex: string, score: string) {
    super(name, age, sex);
    this.score = score;
  }
  show(): void {
    console.log(this.name);
    console.log(this.age);
    console.log(this.score);
    // console.log(this.sex);
  }
}

// 思考题: 如果我们给 constructor 加上 protected 会出现什么情况？

// readonly
class PrintConsole {
  readonly str1: string = "HTML, CSS, JS, VUE, REACT, NODE";
  readonly str2: string;
  readonly str3: string;
  readonly str4: string;

  constructor(str2: string, str3: string, str4: string) {
    this.str2 = str2;
    this.str3 = str3;
    this.str4 = str4;
  }
}

let pc = new PrintConsole(
  "我的头发去哪了, 颈椎康复指南",
  "35岁失业了该怎么办, 外卖月入一万也挺好",
  "活着"
);

5. getter 与 setter

export default {};

class GetNameClass {
  private _fullName: string = "倪妮";

  // 需求:我们就想要在外部进行修改 _fullName 那怎么办？
  get fullName(): string {
    console.log("我是get方法");

    return this._fullName;
  }

  set fullName(newName: string) {
    console.log("我是set方法");

    this._fullName = newName;
  }
}

let startname = new GetNameClass();
startname.fullName = "袁冰妍";

console.log(startname.fullName);