JS의 내장함수

프로그래머스를 풀면서 사용했던 내장함수들을 정리해보았다.

console.log('toUpperCase', 'toLowerCase')
let words = 'Words'
console.log(words.toUpperCase())
console.log(words.toLowerCase())

toUpperCase toLowerCase
WORDS
words

---

console.log('reverse')
let arr = [1, 2, 3, 4, 5]
console.log(arr.reverse())

reverse
[ 5, 4, 3, 2, 1 ]

---

console.log('toString', 'split', 'join')
let number = 1029342
console.log(number.toString())
console.log(typeof(number.toString()))
console.log(number.toString().split(''))
console.log(number.toString().split('').join(''))

toString split join
1029342
string
[
  '1', '0', '2',
  '9', '3', '4',
  '2'
]
1029342