const person = {
    name: "ty",
    age: 21,
    gender: "male",
    fruits: ["apple", "banana", "orange"],
    address: {
        city: "beijing",
        street: "chaoyang"
    }
};

console.log(person.name);           // 点号访问
console.log(person["age"]);         // 方括号访问
console.log(person.address.city);   // 链式访问
console.log(person.fruits[0]);      // 数组元素

person.email = "ty@example.com";    // 添加属性
delete person.gender;               // 删除属性

const { gender, address: { city }, fruits: [fruit1, fruit2] } = person;
console.log(gender, city, fruit1, fruit2);

console.log(Object.keys(person));      // ["name", "age", ...]
console.log(Object.values(person));    // ["ty", 21, ...]
console.log(Object.entries(person));   // [["name","ty"], ["age",21], ...]

const copy = { ...person };                // 浅拷贝
const merged = { ...person, hobby: "code" }; // 合并属性