Function encrypt

Ciphers/AffineCipher.js:72–82

* Encrypt a Affine Cipher * @param {String} str - String to be encrypted * @param {Number} a - A coefficient * @param {Number} b - B coefficient * @return {String} result - Encrypted string

(str, a, b)

 */

function encrypt(str, a, b) {
  let result = ''
  if (isCorrectFormat(str, a, b)) {
    for (let x = 0; x < str.length; x++) {
      const charIndex = findCharIndex(str[x])
      if (charIndex < 0) result += '-1' + ' '
      else result += key.charAt(mod(a * charIndex + b, 26)) + ' '
    }
  }
  return result.trim()
}

/**
 * Decrypt a Affine Cipher