FCC: Caesars Cipher - https://forum.freecodecamp.org/t/freecodecamp-challenge-guide-caesars-cipher/16003

Contributors
1

Challenge link: https://www.freecodecamp.org/learn/javascript-algorithms-and-data-structures/javascript-algorithms-and-data-structures-projects/caesars-cipher
for challenge guide: freeCodeCamp Challenge Guide: Caesars Cipher

Solution 
function rot13(str) {
  let newStr = [];
  let letters = ["A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z"]

  for(let i = 0; i < str.length; i++){
    (/\W/.test(str[i])) 
      ? newStr.push(str[i])
      : (letters[letters.indexOf(str[i]) + 13]) 
      ? newStr.push(str[i].replace(str[i], letters[letters.indexOf(str[i]) + 13]))
      : newStr.push(str[i].replace(str[i], letters[letters.indexOf(str[i]) - 13]))
  }
  return newStr.join("");
}

Tried doing the challenge without String.charCodeAt() or String.fromCharCode() hope this helps.

3

Thank you for your guide post contribution. Unfortunately, we will not be including it in the guide post at this time.

We look forward to your further contribution.