使用typescript接口和抽象类，但不指定泛型类型

// 定义接口
interface Animal {
  name: string;
  age: number;
  eat(food: string): void;
}

// 实现接口
class Dog implements Animal {
  name: string;
  age: number;

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

  eat(food: string): void {
    console.log(`${this.name} is eating ${food}.`);
  }
}

// 定义抽象类
abstract class Shape {
  abstract getArea(): number;
  abstract getPerimeter(): number;
}

// 继承抽象类
class Rectangle extends Shape {
  width: number;
  height: number;

  constructor(width: number, height: number) {
    super();
    this.width = width;
    this.height = height;
  }

  getArea(): number {
    return this.width * this.height;
  }

  getPerimeter(): number {
    return 2 * (this.width + this.height);
  }
}

// 使用接口和抽象类
const dog = new Dog("Bobby", 3);
dog.eat("bone");

const rectangle = new Rectangle(5, 10);
console.log(rectangle.getArea());
console.log(rectangle.getPerimeter());