javascript tip : Spread Syntax - Object,array

spread-syntax.js

//Spread Syntax - Object
const item = { type: 'shirts', size : 'M' };
const detail = { price: 20, made: 'Kores', gender: 'M' };

//bad code 
item['price'] = detail.price;

//bad code
const newObject = new Object;
newObject['type'] = itme.type;
newObject['size'] = itme.size;
newObject['price'] = itme.price;
newObject['made'] = itme.made;
newObject['gender'] = itme.gender;

//bad code
const newObject2 = {
  type: item.type,
  size: item.size,
  price: detail.price,
  made: detail.made,
  gender: detail.gender,
};

//good code 
const chirt0 == Object.assign(item, detail);

//better code 
const shirt = {...item, ...detail, price: 40 };

//spread syntax - arrray
let fruits = ['수박', '귤', '바나나'];

//fruits.push
fruits = [...fruits, '딸기'];

//fruits.unshift
fruits = ['딸기', ...fruits];

const fruits2 = ['메론','피치', '파인애플'];
let combined = fruits.concat(fruits2);
combined = [...fruits, ...fruits2);