README.md

Caesarize

The Caesar Cypher is the simplest of the codes I could find. Simply put, it shifts the alphabet a certain number of letters over to encode a message.

Caesarize.gs

function Caesarize(shiftNum) {
  this.shiftNum = shiftNum; //the number to shift the alphabet
}

Caesarize.prototype.codify = function(sentence) {
  
  var sentenceArr = [];
  var shiftNum = this.shiftNum;
  
  sentence = sentence.toLowerCase();
  
  //private function to get the shifted letter
  var letterize = function(letter) {
    var 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'];
    var pos = letters.indexOf(letter);
    var shiftPos = pos + shiftNum;
    
    if(pos > -1) {
      if(shiftPos < letters.length) {
        return letters[shiftPos];
      } else {
        return letters[shiftPos - letters.length];
      }
    } else {
      return ' ';
    }
  }
  
  for(var i = 0; i < sentence.length; i++) {
    sentenceArr.push(letterize(sentence[i]));
  }
  
  return sentenceArr.join('');
  
}

Caesarize.prototype.uncodify = function(sentence) {
  
  var sentenceArr = [];
  var shiftNum = this.shiftNum;
  
  //private function to unshift each letter in the code
  var deletterize = function(letter) {
    var 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'];
    var pos = letters.indexOf(letter);
    var shiftPos = pos - shiftNum;
    
    if(pos > -1) {
      if(shiftPos >= 0) {
        return letters[shiftPos];
      } else {
        return letters[shiftPos + letters.length];
      }
    } else {
      return ' ';
    }
  }
  
  for(var i = 0; i < sentence.length; i++) {
    sentenceArr.push(deletterize(sentence[i]));
  }
  
  return sentenceArr.join('');
  
}