Javascript Es6 문법

• object shorthand assignment

let name = 'lucas';
let age = 20;
let person ={name, age};
consoel.log(person); // {name:'lucas', age:20}

• Destructuring

let person ={name:'lucas', age:20};
let {name, age} = person;
console.log(name,age); // lucas 20
// 배열에서도 적용
let arr = [1,2,3,4];
let [a,b] = arr;
console.log(a,b); // 1 2
let [A,B,...C] = arr;
console.log(C); // [3,4]

• spread

let person = {name:'lucas', age:20};
let person2 = {...person}; // 깊은 복사
let person3 = person; // 얕은 복사, reference값만 복사 원본과 함께 변경됨
console.log(person == person2); // false
console.log(person == person3); // true
//깊은 복사시 필요한 내용 추가나 변경도 가능
let person4 = {...person,address="here"};
console.log(person4) = {name:'lucas', age:20, address="here"};
let person5 = {...person,name='julie'};
console.log(person4) = {name:'julie', age:20};
let a = [1,2,3];
let b = [...a,4,5];
console.log(b); // [1,2,3,4,5]