#3. 객체 메소드(object methods), 계산된 프로퍼티(Computed property)

// Conputed property
let a = 'age';

const User = {
   name: 'Mike',
   [a]: 30
}

console.log(User.[a]); // 30

const user = {
  [1 + 4]: 5,
  ["안녕"+"하세요"]: "Hello"
}

console.log(user); // {5: 5, 안녕하세요: 'Hello'}

Methods

Object.assign(): 객체 복제

const user = {
	name: 'Mike',
	age: 30
}

const cloneUser = user;

console.log(user); // {name: 'Mike', age: 30}
console.log(cloneUser); // {name: 'Mike', age: 30}

cloneUser.name = 'Tom'

console.log(user); // {name: 'Tom', age: 30}
console.log(cloneUser); //{name: 'Tom', age: 30}

// 하나의 변수에 동일하게 접근

--------------------------------------
const user = {
	name: 'Mike',
	age: 30
}

const newUser = Object.assign({}, user); // {} -> 초기값!

console.log(user); // {name: 'Mike', age: 30}
console.log(newUser); // {name: 'Mike', age: 30}

newUser.name = 'Tom'

console.log(user); // {name: 'Mike', age: 30}
console.log(newUser); //{name: 'Tom', age: 30}
---------------------------------------
const user = {
	name: 'Mike',
	age: 30
}

const newUser = Object.assign({gender:'male'}, user);

console.log(newUser); // {gender: 'male', name: 'Mike', age: 30}
----------------------------------------
const user = {
	name: 'Mike',
	age: 30
}

const newUser = Object.assign({name:'Tom'}, user);

console.log(newUser); // {name: 'Mike', age: 30}
-----------------------------------------
const user = {
  name: 'Mike'
}
const info1 = {
  age: 30
}
const info2 = {
  gender: 'male'
}

Object.assign(user, info1, info2)

console.log(user) // {name: 'Mike', age: 30, gender: 'male'}

Object.keys(): 키 배열 반환

const user = {
  name: 'Mike',
  age: 30,
  gender: 'male'
}

const result = Object.keys(user);

console.log(result); // ['name', 'age', 'gender']

Object.values(): 값 배열 반환

const user = {
  name: 'Mike',
  age: 30,
  gender: 'male'
}

const result = Object.values(user);

console.log(result); // ['Mike', 30, 'male']

Object.entries(): 키/값 배열 반환

const user = {
  name: 'Mike',
  age: 30,
  gender: 'male'
}

const result = Object.entries(user);

console.log(result); 

Object.fromEntries(): 키/값 배열을 객체로

const arr = [
  ["name", "Mike"],
  ["age", 30],
  ["gender", "male"]
];

const result = Object.fromEntries(arr);

console.log(result); // {name: 'Mike', age: 30, gender: 'male'}

let n = "name"
let a = "age"

const user = {
  [n]: "Mike",
  [a]: 30
};

console.log(user); // {name: 'Mike', age: 30}