[JavaScript] 할당, 구조분해할당

• 할당
  • ex) let x, y;
    • x = y = 9;
    • x +=y; x %= y; x &= y; x ^= y;
  • object
    • ex) const u = {id: 1, name: ‘hong’, age: 29};
      • let {id, name, addr} = u;
      • let {id, …info} = u;
      • ({id, name} = u);
    • const arr = [1, 2, 3, 4, 5];
      • let [a, b, …c] = arr;
      • [a, b] = [b, a];

 

• 구조 분해 할당(destructuring)
  • Object Destructuring
    • const {id, name} = {id:1, name:’Hong’};
  • Array / Iterator Destructuring
    • const [a, b] = [1, 2];
  • Default Value Destructuring
    • const {id, name, addr = ‘Seoul’} = {id:1, name:’Hong’, add:’Busan’};
  • Arguments Destructuring
    • function fn({a, b}) {…}
    • fn({a:1, b:2});
  • Class Destructuring
    • const x = new A(1, 2);
    • const {a, b} = x;
  • Array To Object Destructuring
    • const {’0’:a1, ‘1’:a2} = [1, 2];
  • ex) const fn = ({age}) => age;
    • ⇒ (화살표)는 return을 품고 있다.