在 js 中如何实现继承

class Animal {
  constructor(name) {
    this.name = name;
  }
 
  hello() {
    console.log("hello");
  }
}
 
class Dog extends Animal {
  constructor(name, say) {
    super(name);
    this.say = say;
  }
}

function Animal(name) {
  this.name = name;
}
 
Animal.prototype.hello = () => {
  console.log("hello");
};
 
function Dog(name, say) {
  // 01 继承属性
  Animal.call(this, name);
  this.say = say;
}
 
// 02 通过连接原型链完成继承
Dog.prototype = Object.create(Animal.prototype);
 
// 03 再加上 constructor
Dog.prototype.constructor = Dog;
// Reflect.defineProperty(Dog.prototype, "constructor", {
//  value: Dog,
//  enumerable: false, // 不可枚举
//  writable: true
// })