JSFiddle - React, Tailwind, and code Playground

HTML

<input id="input1" type="text" onkeydown="if (event.keyCode == 13) getParameters()" value="color=red"/> Press Enter
<div id="ccc">
<div id="test_div">test_div</div>
</div>
<!-- http://stackoverflow.com/questions/13207927/switch-statement-multiple-cases-in-javascript -->
<div id="monitor_test_div">monitor_test_div</div>

CSS

input {width: 250px;}
#test_div {
    display: inline-block;
    border: 1px solid rgb(160, 160, 160);
    margin: 5px 0px 4px 1px;
    padding: 1px 8px;
    font-size: 20px;
    font-weight: bold;
}
br {
    display: none;
}

JavaScript

function getParameters() {
  var searchString = document.getElementById('input1').value,
      params = searchString.split("&"),
      hash = {};

  if (searchString == "") return {};
  for (var i = 0; i < params.length; i++) {
    var val = params[i].split("=");
    hash[unescape(val[0])] = unescape(val[1]);
  }
    console.log(hash);
  //return hash;
    
  switch (val[0]){
        case "src":
        case "width":
        case "align":
            //alert(val[1]);
            $.each(hash, function( attribute, value ) {
              test_div.setAttribute(attribute,value);
            });
            break;
        case "color":
            //alert(val[1]);
            $.each(hash, function( attribute, value ) {
              test_div.style[attribute]=value;
            });
            break;
        //default:
         //   alert('default');
           // break;
    }
    
  monitor_test_div.innerText = ccc.innerHTML;
}