[JavaScript] destructuring

구조분해할당 : destructuring( de + structure  + ing)

de = not

structure = 구조

 

배열(array)에서의 구조분해할당

let [value1,value2] = [1,"new"];
console.log(value1);
console.log(value2);

let arr = ["1","2","3"];
let [a,b,c] = arr;
console.log(a);
console.log(b);
console.log(c);

let arr = ["1","2","3"];
let [a,b,c,d] = arr; // d추가
console.log(a);
console.log(b);
console.log(c);
console.log(d);

let arr = ["1","2","3"];
let [a,b,c,d = 4] = arr; // d에 값 초기화
console.log(a);
console.log(b);
console.log(c);
console.log(d);

 

 

객체(object)에서의 구조분해할당

let {name,age} = {
    name: "asd",
    age: 10
};
console.log(name,age);

let {name,age} = user;
console.log(name,age);

let user = {
    name: "asd",
    age: 10
};
let {name : newname, age:newage} = user;
console.log(newname,newage);
// newname 에 "asd"가 할당, newage에 10이 할당

let {name,age,birthday} = user;
console.log(name,age,birthday);

let {name,age,birthday = "today"} = user;
console.log(name,age,birthday);