JSFiddle - React, Tailwind, and code Playground

by RomanTarasiuk

HTML

<!DOCTYPE html>
<html>
<body>
  <textarea id="listOne"></textarea>
  <br>
  <textarea id="listTwo"></textarea>
  <br>
  <textarea id="results"></textarea>
  <br>
  <button onclick="processIt()">Process</button>
  
<script>
processIt = function() {
  var listOneData = document.getElementById('listOne').value;
  var listTwoData = document.getElementById('listTwo').value;

  var splittedOne = listOneData.split(',');
  var splittedTwo = listTwoData.split(',');

  var result = [];

  for (var i = 0; i < splittedOne.length; i++) {
    if (splittedTwo.indexOf(splittedOne[i]) == -1) {
      result.push(splittedOne[i]);
    }
  }

  document.getElementById('results').value = result.join(',');
}
</script>
</body>
</html>