[JS] 데이터 - 전개 연산자

전개 연산자 ...

const fruits = ['apple', 'banana', 'cherry']

console.log(fruits)//['apple', 'banana', 'cherry']
console.log(...fruits)//apple banana cherry
//console.log('apple', 'banana', 'cherry')

function toObject(a,b,c) {
  return {
    a: a,
    b: b,
    c: c
  }
}

console.log(toObject(...fruits))
console.log(toObject(fruits[0], fruits[1], fruits[1]))

const fruits = ['apple', 'banana', 'cherry','orange']

console.log(fruits)//['apple', 'banana', 'cherry']
console.log(...fruits)//apple banana cherry
//console.log('apple', 'banana', 'cherry')

function toObject(a,b, ...c) {  // ...c : rest parameter 나머지 매개변수 
  return {
    a: a,
    b: b,
    c: c
  }
}

console.log(toObject(...fruits)) //{a: 'apple', b: 'banana', c: ['cherry', 'orange']}

간단하게 나타내면! key와 받는 내용이 동일하면 축약할 수 있음!!

const fruits = ['apple', 'banana', 'cherry','orange']

console.log(fruits)//['apple', 'banana', 'cherry']
console.log(...fruits)//apple banana cherry
//console.log('apple', 'banana', 'cherry')

const toObject = (a,b, ...c) => ({a, b, c})

console.log(toObject(...fruits)) //{a: 'apple', b: 'banana', c: ['cherry', 'orange']}