了解 JavaScript 原型：继承和方法共享综合指南

function Person(name, age) {
  this.name = name;
  this.age = age;
}

// 向Person原型添加方法
Person.prototype.greet = function() {
  console.log("Hello, " + this.name);
};

const person1 = new Person("John", 30);
person1.greet(); // 输出: "Hello, John"

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

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

function Dog(name) {
  Animal.call(this, name); // 继承Animal的属性
}

Dog.prototype = Object.create(Animal.prototype); // 设置原型链
Dog.prototype.constructor = Dog; // 修正构造函数引用

const dog1 = new Dog("Buddy");
dog1.speak(); // 输出: "Buddy makes a sound."

function Car(make, model) {
  this.make = make;
  this.model = model;
}

// 向原型添加方法
Car.prototype.displayInfo = function() {
  console.log(this.make + " " + this.model);
};

const car1 = new Car("Toyota", "Corolla");
car1.displayInfo(); // 输出: "Toyota Corolla"

function Student(name, grade) {
  this.name = name;
  this.grade = grade;
}

Student.prototype.study = function() {
  console.log(this.name + " is studying.");
};

const student1 = new Student("Alice", "A");
console.log(student1.__proto__ === Student.prototype); // true

function Animal() {
  this.legs = 4;
}

Animal.prototype.walk = function() {
  console.log("Walking...");
};

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

Dog.prototype = Object.create(Animal.prototype); // 继承Animal
Dog.prototype.constructor = Dog; // 修正构造函数引用

const dog2 = new Dog("Rex");
console.log(dog2.legs); // 输出: 4
dog2.walk(); // 输出: "Walking..."

const obj = {};
const proto = { greet() { console.log("Hello!"); } };

Object.setPrototypeOf(obj, proto);
obj.greet(); // 输出: "Hello!"