js object 初始化

let person = {
    name: 'Alice'
};

// 正确访问
console.log(person.name); // 输出: Alice

// 错误访问
console.log(person.age); // 输出: undefined

let person = {
    name: 'Alice',
    greet: function() {
        console.log('Hello, my name is ' + this.name);
    }
};

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

// 错误调用
person.sayHello(); // 抛出 TypeError: person.sayHello is not a function

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

    // 使用箭头函数确保 this 指向正确
    this.greet = () => {
        console.log('Hello, my name is ' + this.name);
    };
}

let alice = new Person('Alice', 25);
setTimeout(alice.greet, 1000); // 输出: Hello, my name is Alice