接口

1. 接口使用举例

// interface 只能为对象指定类型
interface IPerson {
  name: string;
  age: number;
  greet(name: string): void;
  sayHi: () => void;
}

// 类型别名, 可以为任意类型指定别名
type IPerson1 = {
  name: string;
  age: number;
  greet(name: string): void;
  sayHi: () => void;
};

let person: IPerson = {
  name: "tom",
  age: 20,
  greet(name) {
    console.log(name);
  },
  sayHi() {
    console.log("hi");
  },
};

let person1: IPerson1 = {
  name: "tom",
  age: 20,
  greet(name) {
    console.log(name);
  },
  sayHi() {
    console.log("hi");
  },
};
console.log(person);
console.log(person1);
person.greet("tom");
person1.greet("jim");

// 接口继承
interface Point2D {
  x: number;
  y: number;
}
interface point3D extends Point2D {
  z: number;
}
let p: point3D = {
  x: 0,
  y: 1,
  z: 2,
};
console.log(p);