[Javascript] mutable(변화기쉬운) 객체 & immutable(안변하는) 객체

1. mutable 객체

1) Array

// mutable 객체
let fruits = ['banana', 'apple', 'melon']
let clonefruits = fruits;

clonefruits.push('plum');

console.log('clonefruits', clonefruits)
console.log('fruits', fruits)

 

2) Object

let myInfo = {
  age : 18,
  email : 'sal10@gmail.com'
}
let cloneMyInfo = myInfo

cloneMyInfo.age = cloneMyInfo.age + 1

console.log('cloneMyInfo', cloneMyInfo);
console.log('myInfo', myInfo)

 

2. immutable 객체

1) 문자열

//immutable 객체
let myName = 'James'
let cloneName = myName;

cloneName = cloneName + 'hello';

console.log('cloneName', cloneName)
console.log('myName', myName)

 

2) 숫자

let count = 1
let cloneCount = count;

cloneCount = cloneCount + 2;

console.log('cloneCount', cloneCount)
console.log('count', count)