js

javascript ๊ฐ์ฒด ๋ฉ”์†Œ๋“œ(Object methods), ๊ณ„์‚ฐ๋œ ํ”„๋กœํผํ‹ฐ(Computed propery)

์œถโ‰ 2022. 8. 29. 23:30
let n = "name";
let a = "age";

const user = {
    [n] : "Mike",
    [a] : 30,
    [1+4] : 5,
};

console.log(user);

๊ฒฐ๊ณผ

{5: 5, name: 'Mike', age: 30}

    5: 5age: 30

    name: "Mike"

    [[Prototype]]: Object

 

 

- ์–ด๋–ค๊ฒŒ ํ‚ค๊ฐ€ ๋  ์ง€ ๋ชจ๋ฅผ ๋•Œ ์œ ์šฉ

function makeObj(key,val) {
    return {
        [key] : val,
    };
}

const obj = makeObj("๋‚˜์ด", 33);

console.log(obj);

๊ฒฐ๊ณผ

{๋‚˜์ด: 33}

 

-๊ฐ์ฒด ๋ฉ”์†Œ๋“œ

const user = {
    name: "Mike",
    age:"30",
};

const user2 = user;
user2.name = "Tom"

console.log(user);
console.log(user2);

 

๊ฒฐ๊ณผ

{name: 'Tom', age: '30'}
{name: 'Tom', age: '30'}

๊ธฐ์กด์— ์žˆ๋˜ user์™€ user2์˜ ์ด๋ฆ„์ด ๋‘˜ ๋‹ค ๋ณ€๊ฒฝ๋จ

๋ชจ๋‘ ํ•˜๋‚˜์˜ ๊ฐ์ฒด๋กœ ๋ด„

 

-> ๋ณต์‚ฌํ•  ๋•Œ๋Š” object ๋ฉ”์†Œ๋“œ ์‚ฌ์šฉ

 

-Object.assign

const user = {
    name: "Mike",
    age:"30",
};

const user2 = Object.assign({},user);
user2.name = "Tom"

console.log(user);
console.log(user2);

 

Object.assign({},user) ์—์„œ {}์ด ์ดˆ๊ธฐ๊ฐ’์— ํ•ด๋‹น
 
๊ฒฐ๊ณผ
{name: 'Mike', age: '30'}
{name: 'Tom', age: '30'}
-> user์˜ ๊ฐ’์ด user2์— ๋ณต์‚ฌ๋˜์–ด์„œ console.log(user2)๋กœ ๊ฐ’ ๋…ธ์ถœ
 
 
- Object.keys
const user = {
    name: "Mike",
    age:"30",
};

const result = Object.keys(user);

console.log(result);
 
 
๊ฒฐ๊ณผ
(2) ['name', 'age']

keys์— ํ•ด๋‹นํ•˜๋Š” ๊ฐ’๋งŒ  ๋ฐฐ์—ด๋กœ ๋ฐ˜ํ™˜

 

- Object.values

const user = {
    name: "Mike",
    age:"30",
};

const result = Object.values(user);

console.log(result);

๊ฒฐ๊ณผ

(2) ['Mike', '30']

values์— ํ•ด๋‹นํ•˜๋Š” ๊ฐ’๋งŒ ๋ฐฐ์—ด๋กœ ๋ฐ˜ํ™˜

 

-Object.entries

const user = {
    name: "Mike",
    age:"30",
};

const result = Object.entries(user);

console.log(result);

 

๊ฒฐ๊ณผ

(2) [Array(2), Array(2)]

    0: (2) ['name', 'Mike']

    1: (2) ['age', '30']

    length: 2

    [[Prototype]]: Array(0)

 

- Object.fromEntries

let arr = [
    ['mon',' ์›”'],
    ['tue','ํ™”'],
];

const result = Object.fromEntries(arr);
console.log(result);

๊ฒฐ๊ณผ

{mon: ' ์›”', tue: 'ํ™”'}

๋ฐฐ์—ด์„ ๊ฐ์ฒด๋กœ ๋งŒ๋“ฆ