Encoding a string and display string output in Javascipt

Question

I am writing a code to encode a string and it hopes to display the encoded string in a div. However, it shows nothing. May I know what's wrong with my code? Thank you.

HTML:

<div id="c"></div>

Javascript:

function encode() {
  var a = "abcde";
  a = unescape(a);
  var c = String.fromCharCode(a.charCodeAt(0) - a.length);
  for(var i = 1; i < a.length; i++){
    c += String.fromCharCode(a.charCodeAt(i) - c.charCodeAt(i - 1));
  }
  return c;
  document.write(c)
}

Answer 1

You're writing the output to the document after returning from the function. Try something like this:

function encode (){
  var a = "abcde";
  a = unescape(a);
  var c = String.fromCharCode(a.charCodeAt(0) - a.length);
  for(var i=1; i<a.length; i++){
      c+=String.fromCharCode(a.charCodeAt(i) - c.charCodeAt(i-1));
  }
  return c;
}

document.getElementById("c").innerText = encode();

<div id="c"></div>