ES6的类语法如何实现继承

class Animal {
  constructor(name) {
    this.name = name;
  }

  speak() {
    console.log(`${this.name} makes a sound.`);
  }
}

class Dog extends Animal {
  constructor(name, breed) {
    super(name); // 调用父类的构造函数
    this.breed = breed;
  }

  speak() {
    super.speak(); // 调用父类的speak方法
    console.log(`${this.name} barks.`);
  }
}

const dog = new Dog('Buddy', 'Golden Retriever');
dog.speak(); // 输出 "Buddy makes a sound." 和 "Buddy barks."

class Animal {
    constructor(name) {
        this.name = name;
    }
}

class Dog extends Animal {
    constructor(name, breed) {
        this.breed = breed; // 错误：必须先调用super()
        super(name);
    }
}

class Animal {
    constructor(name) {
        this.name = name;
    }
}

class Dog extends Animal {
    constructor(name, breed) {
        super(name); // 正确：先调用super()
        this.breed = breed;
    }
}

function Animal(name) {
  this.name = name;
}

Animal.prototype.speak = function() {
  console.log(this.name + ' makes a sound.');
};

function Dog(name, breed) {
  Animal.call(this, name); // 模拟super()
  this.breed = breed;
}

Dog.prototype = Object.create(Animal.prototype); // 设置原型链
Dog.prototype.constructor = Dog; // 修正constructor指向

Dog.prototype.speak = function() {
  Animal.prototype.speak.call(this); // 调用父类方法
  console.log(this.name + ' barks.');
};

var dog = new Dog('Buddy', 'Golden Retriever');
dog.speak(); // 输出 "Buddy makes a sound." 和 "Buddy barks."

const barkable = (Base) => class extends Base {
  bark() {
    console.log('Woof!');
  }
};

const tailWaggable = (Base) => class extends Base {
  wagTail() {
    console.log('Tail wagging!');
  }
};

class Animal {
  constructor(name) {
    this.name = name;
  }
}

class Dog extends barkable(tailWaggable(Animal)) {
  constructor(name) {
    super(name);
  }
}

const dog = new Dog('Buddy');
dog.bark(); // 输出 "Woof!"
dog.wagTail(); // 输出 "Tail wagging!"