JavaScript Caesar Cipher
const caesarEncoded = (s, n) => {
let alphabet = 'abcdefghijklmnopqrstuvwxyz'
let lc = alphabet.replace(/\s/g, '').toLowerCase().split('')
let uc = alphabet.replace(/\s/g, '').toUpperCase().split('')
return Array.from(s)
.map((v) => {
if (lc.indexOf(v.toLowerCase()) === -1 || uc.indexOf(v.toUpperCase()) === -1) {
return v
}
const lcEncryptIndex = (lc.indexOf(v.toLowerCase()) + n) % alphabet.length
const lcEncryptedChar = lc[lcEncryptIndex]
const ucEncryptIndex = (uc.indexOf(v.toUpperCase()) + n) % alphabet.length
const ucEncryptedChar = uc[ucEncryptIndex]
return lc.indexOf(v) !== -1 ? lcEncryptedChar : ucEncryptedChar
})
.join('')
}
const caesarDecoded = (s, n) => {
let alphabet = 'abcdefghijklmnopqrstuvwxyz'
let lc = alphabet.replace(/\s/g, '').toLowerCase().split('')
let uc = alphabet.replace(/\s/g, '').toUpperCase().split('')
return Array.from(s)
.map((v) => {
if (lc.indexOf(v.toLowerCase()) === -1 || uc.indexOf(v.toUpperCase()) === -1) {
return v
}
let lcEncryptIndex = (lc.indexOf(v.toLowerCase()) - n) % alphabet.length
lcEncryptIndex = lcEncryptIndex < 0 ? lcEncryptIndex + alphabet.length : lcEncryptIndex
const lcEncryptedChar = lc[lcEncryptIndex]
let ucEncryptIndex = (uc.indexOf(v.toUpperCase()) - n) % alphabet.length
ucEncryptIndex = ucEncryptIndex < 0 ? ucEncryptIndex + alphabet.length : ucEncryptIndex
const ucEncryptedChar = uc[ucEncryptIndex]
return lc.indexOf(v) !== -1 ? lcEncryptedChar : ucEncryptedChar
})
.join('')
}
console.log(caesarEncoded('XVCJ9', 5))
console.log(caesarDecoded('CAHO9', 5))
Restu Wahyu Saputra