JSFiddle - React, Tailwind, and code Playground

HTML

<form>
  <input type="button" value="whatever" id="hog" />
  <input type="text" id="thename" />
</form>

CSS

#hog {color:blue;font-size:1.3em;border:0px;background-color:transparent;}

JavaScript

// JavaScript Document
var one ="hello there";
var two = document.getElementById("hog");
var three = document.getElementById("thename");

two.onclick = function() {
three.value = one;
};