JSFiddle - React, Tailwind, and code Playground

HTML

<input id="firstInput" type="text"/>
<textarea id="txtarea" rows="20" cols="60"></textarea>

JavaScript

var inputElement = document.getElementById("firstInput");
var area = document.getElementById("txtarea");

inputElement.onfocus = function(){
    area.value += "focus \n";
};

inputElement.onblur = function(){
    area.value += "blur \n";
};