//TODO Mutations

// How to avoid mutation of the object

// 1st method

const Chinese = {

HongKong: "Cantonese",

Taiwan: "Mandarin",

Shanghai: "Shanghainese",

};

const ChineseCopy = Object.assign({}, Chinese); // copy without mutation. "{}" is an empty object

ChineseCopy.HongKong = "Mandarin";

console.log(Chinese);

console.log(ChineseCopy);

// But this method is not recommended, because it doesn't work with nested objects.

// 2nd method

const Music = {

pop: "The Weeknd",

phonk: "Fluxxwave",

rap: "Eminem",

};

const MusicCopy = { ...Music }; // "..." is a spread operator.

MusicCopy.pop = "Drake";

console.log(Music);

console.log(MusicCopy);

// This method doesn't work with nested objects neither.

// 3rd method

const book = {

British: "Joan Rowling",

Japanese: "Haruki Murakami",

Chinese: "Mo Yan",

Korean: {

name: "Han Kang",

book: "The Vegetarian",

},

};

const bookCopy = JSON.parse(JSON.stringify(book)); // copy without mutation at all

bookCopy.Korean.name = "warrior";

bookCopy.British = "Stephen King";

console.log(book);

console.log(bookCopy);