Caesars Cipher not working : prints double whitespace & "C↵" to console

1

Hello!

Not the most refined code but I think I’m almost there. My goal is to solve then refine where I can. Anyways, I’m getting weird characters added to my code somehow.

["F", "R", "E", "E", " ", "C", "O", "Da", "E", " ", "C↵", "A", "M", "P"]

The above array was copied/pasted directly from chrome js console. It is the result of console.log(result);

Looking at the above array, three odd characters are coming up in my code :
1)“Da” - ok, when looking at this while I type this topic preview and in my js console there is no “Da” it looks like “D”. When I submit this topic it comes up “Da”. ??

2)whitespace - the last whitespace between “E” & “C↵” in my chrome js console actually looks like a string with whitespace but two characters long such as “blank blank” and not just “blank”. It is not showing in the preview as I type this topic.

3)“C↵” - where the heck did this come from??

I would like it to look like :

["F", "R", "E", "E", " ", "C", "O", "D", "E", " ", "C", "A", "M", "P"]

Does anyone know why I get a whitespace character with twice the whitespace, the very odd "C↵" and why “D” comes out “Da” ? Bizarre!

 function rot13(str) {
      //string to array : 
      var arr = str.split(''); 
      console.log(arr);// ["S", "E", "R", "R", " ", "P", "B", "Q", "R", " ", "P", "N", "Z", "C"]
      //empty array will hold unicode 
      var unicode = [];
      //empty array that will hold shifted unicode 
      var shifted = [];
      //loop through arr and change each letter to unicode :
     for(var i = 0; i < arr.length; i++) {
          var toUnicode = arr[i].charCodeAt(arr[i]);
          unicode.push(toUnicode);
        }
      console.log(unicode);//[83, 69, 82, 82, 32, 80, 66, 81, 82, 32, 80, 78, 90, 67]
      //we need to loop through array unicode and check whether each item needs
      //to be shifted by +13 or by -13
      //we also need a place to put the new values
      for(var j = 0; j < unicode.length; j++) {
        if(unicode[j] == 32) {
          shifted.push(unicode[j]);
        }
        else if (unicode[j] >= 65 && unicode[j] <= 77 ) {
            shifted.push(unicode[j] + 13);
        } else {
            shifted.push(unicode[j] - 13);
       }
      }
      console.log(shifted);//[70, 82, 69, 69, 32, 67, 79, 68, 69, 32, 67, 65, 77, 80]
      var result = shifted.map(String.fromCharCode);
      console.log(result);//["F", "R", "E", "E", " ", "C", "O", "Da", "E", " 	", "C↵", "A", "M", "P"]

    }

    rot13("SERR PBQR PNZC");
2

Hi.

It’s too late here, to study or discover your code, so I’ll give you some tips:

  1. You need to split your str (string):
    Explanation: you have got from string “LOL” array of [“L”, “O”, “L”]
  2. Then you need to transform your array of string to array of numbers using ASCII table:
    Explanation: transform this array [“L”, “O”, “L”] to this one [76, 79, 76]
  3. The next step is using for loop (for example) to shift letters:
    Explanation: conver this [76, 79, 76] to this one [89, 66, 89]
  4. Then you can convert numbers to letters:
    Explanation: [89, 66, 89] —> [“Y”, “B”, “Y”]
  5. The last step is to convert array to string:
    Explanation: [“Y”, “B”, “Y”] —> “YBY”

Useful functions:
charCodeAt()
fromCharCode()
push()
split()

Hope, this tips will help you. Good luck!

4

Just wanted to send a big thanks! for explaining this. It is not always easy to figure out what is happening under the hood in JavaScript and you’re explanation is an enlightenment. I tried the code and it works great.

5

Thanks again for everyone’s help!

My current working solution. If anyone has suggestions on how I can tighten this up I would appreciate it :

function rot13(str) {
  var arr = str.split(''); 
  var unicode = [];
  var shifted = [];
 for(var i = 0; i < arr.length; i++) {
      var toUnicode = arr[i].charCodeAt(arr[i]);
      unicode.push(toUnicode);
    }
for(var j = 0; j < unicode.length; j++) {
    if(unicode[j] == 32) {
      shifted.push(unicode[j]);
    } else if(unicode[j] == 32) {
      shifted.push(unicode[j]);
    } else if(unicode[j] == 33) {
      shifted.push(unicode[j]);
    } else if(unicode[j] == 63) {
      shifted.push(unicode[j]);
    } else if(unicode[j] == 46) {
      shifted.push(unicode[j]);
    } else if (unicode[j] >= 65 && unicode[j] <= 77 ) {
        shifted.push(unicode[j] + 13);
    } else {
        shifted.push(unicode[j] - 13);
   }
  }
  var result = shifted.map(function(item) { return String.fromCharCode(item) }).join('');  

return result;

}