Function ROT13

Ciphers/ROT13.js:8–22

* @function ROT13 * @description - ROT13 ("rotate by 13 places", sometimes hyphenated ROT-13) is a simple letter substitution cipher that replaces a letter with the 13th letter after it in the alphabet. ROT13 is a special case of the Caesar cipher which was developed in ancient Rome. Because there

(str)

 * @return {String} decrypted string
 */
function ROT13(str) {
  if (typeof str !== 'string') {
    throw new TypeError('Argument should be string')
  }

  return str.replace(/[a-z]/gi, (char) => {
    const charCode = char.charCodeAt()

    if (/[n-z]/i.test(char)) {
      return String.fromCharCode(charCode - 13)
    }

    return String.fromCharCode(charCode + 13)
  })
}

export default ROT13