JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<head>
<script language="javascript">
function selectChanged () { 
    var obj = document.getElementById("cCode"); 
    var courseTitle = document.getElementById("courseTitle"); 
    courseTitle.value = obj.options[obj.selectedIndex].getAttribute('courseTitle', 2);
}
</script>
</head>
<body>
<select name="cCode" id="cCode" onchange="selectChanged();">
    <option courseTitle="Course Title 1">Subject Code 1</option>
    <option courseTitle="Course Title 2">Subject Code 2</option>
    <option courseTitle="Course Title a">Subject Code a</option>
</select>
<input id="courseTitle" type="text" name="sSubject" disabled value="Subject"/>
</body>
</html>