JSFiddle - React, Tailwind, and code Playground

by K.J Ye

HTML

<textarea id="mytext"></textarea>

<select id="dropdown">
    <option value="">None</option>
    <option value="text1">text1</option>
    <option value="text2">text2</option>
    <option value="text3">text3</option>
    <option value="text4">text4</option>
</select>

JavaScript

var mytextbox = document.getElementById('mytext');
var mydropdown = document.getElementById('dropdown');

mydropdown.onchange = function(){
     mytextbox.value = mytextbox.value  + this.value;
}