Caeser code

by Евгений

HTML

<input class="text" oninput="encode()" />
<input type="number" oninput="encode()" class="offset" />
<button onclick="encode()">encode</button>
<button onclick="decode()">decode</button>
<div class="result"></div>

JavaScript

const alphabet = 'абвгдеёжзийклмнопрстуфхцчшщъыьэюя';
const alphabetC = 'АБВГДЕЁЖЗИЙКЛМНОПРСТУФХЦЧШЩЪЫЬЭЮЯ';
const code = (alphabet + alphabet + alphabetC + alphabetC).split('');

function encode() {
  const text = document.querySelector('.text').value || 'bla';
  const offset = document.querySelector('.offset').value || 1;
  const result = document.querySelector('.result');

  const encoded = text.split('').map((symbol) => {
    const index = code.findIndex((codeSymbol) => codeSymbol === symbol);

    if (index === -1) {
      console.error('Not found: ', symbol);
      return symbol;
    }
    return code[index + +offset];
  }).join('');


  result.textContent = encoded;
}

function decode() {
  const result = document.querySelector('.result');
  result.textContent = 'de-bla-bla'
}