在JavaScript中创建对象的可行方法小结

// 创建一个简单的对象
const person = {
  name: "Alice", // 属性
  age: 25,       // 属性
  greet: function() { // 方法
    console.log(`Hello, my name is ${this.name}`);
  }
};

person.greet(); // 输出：Hello, my name is Alice

// 使用对象字面量创建对象
const book = {
  title: "JavaScript高级程序设计",
  author: "Nicholas C. Zakas",
  getDetails: function() {
    return `${this.title} by ${this.author}`;
  }
};

console.log(book.getDetails()); // 输出：JavaScript高级程序设计 by Nicholas C. Zakas

// 定义构造函数
function Car(brand, color) {
  this.brand = brand; // 属性
  this.color = color; // 属性
  this.start = function() { // 方法
    console.log(`${this.brand} car started`);
  };
}

// 创建实例
const myCar = new Car("Toyota", "Red");
myCar.start(); // 输出：Toyota car started

// 定义构造函数
function Animal(name) {
  this.name = name;
}

// 在原型上定义方法
Animal.prototype.speak = function() {
  console.log(`${this.name} makes a sound.`);
};

// 创建实例
const dog = new Animal("Dog");
dog.speak(); // 输出：Dog makes a sound.

// 定义原型对象
const animalPrototype = {
  speak: function() {
    console.log(`${this.name} makes a sound.`);
  }
};

// 使用 Object.create 创建对象
const cat = Object.create(animalPrototype);
cat.name = "Cat";
cat.speak(); // 输出：Cat makes a sound.

// 定义类
class Person {
  constructor(name, age) {
    this.name = name;
    this.age = age;
  }

  greet() {
    console.log(`Hello, my name is ${this.name}`);
  }
}

// 创建实例
const alice = new Person("Alice", 25);
alice.greet(); // 输出：Hello, my name is Alice

const config = {
  debugMode: true,
  maxConnections: 100,
  timeout: 5000
};

class User {
  constructor(id, username, email) {
    this.id = id;
    this.username = username;
    this.email = email;
  }

  displayInfo() {
    console.log(`User ID: ${this.id}, Username: ${this.username}, Email: ${this.email}`);
  }
}

const user1 = new User(1, "alice", "alice@example.com");
user1.displayInfo(); // 输出：User ID: 1, Username: alice, Email: alice@example.com

function Product(name, price) {
  this.name = name;
  this.price = price;
}

Product.prototype.discount = function(amount) {
  this.price -= amount;
  console.log(`${this.name} is now priced at $${this.price}`);
};

const product = new Product("Laptop", 1000);
product.discount(100); // 输出：Laptop is now priced at $900

function createVehicle(type, brand) {
  const vehicle = {};
  if (type === "car") {
    vehicle.type = "Car";
    vehicle.drive = function() {
      console.log(`${brand} car is driving.`);
    };
  } else if (type === "bike") {
    vehicle.type = "Bike";
    vehicle.ride = function() {
      console.log(`${brand} bike is riding.`);
    };
  }
  return vehicle;
}

const car = createVehicle("car", "Toyota");
car.drive(); // 输出：Toyota car is driving.

const bike = createVehicle("bike", "Honda");
bike.ride(); // 输出：Honda bike is riding.

const constants = Object.freeze({
  PI: 3.14159,
  E: 2.71828
});

constants.PI = 3; // 不会生效
console.log(constants.PI); // 输出：3.14159