JavaScript面向对象编程精髓

function Person(name) {
  this.name = name;
}
Person.prototype.greet = function() {
  return `Hello, I'm ${this.name}`;
};

const alice = new Person("Alice");
console.log(alice.greet()); // "Hello, I'm Alice"

class Animal {
  constructor(type) {
    this.type = type;
  }
  speak() {
    console.log(`${this.type} makes a sound`);
  }
}
const dog = new Animal("Dog");
dog.speak(); // "Dog makes a sound"

function Dog(name, breed) {
  Person.call(this, name); // 继承属性
  this.breed = breed;
}
Dog.prototype = Object.create(Person.prototype);
Dog.prototype.constructor = Dog;

Dog.prototype.bark = function() {
  return "Woof!";
};

class Dog extends Animal {
  constructor(name, breed) {
    super(name);
    this.breed = breed;
  }
  bark() {
    console.log("Woof!");
  }
}

function Counter() {
  let count = 0; // 私有变量

  this.increment = function() {
    count++;
  };
  this.getCount = function() {
    return count;
  };
}

class Counter {
  #count = 0;

  increment() {
    this.#count++;
  }

  getCount() {
    return this.#count;
  }
}