JSFiddle - React, Tailwind, and code Playground

HTML

<input type="text" id="txtBx" />

JavaScript

document.getElementById("txtBx").value = null;
alert("test 1 textbox is null \n" +  (document.getElementById("txtBx").value == null));

alert("test 2 textbox is empty string \n" +  (document.getElementById("txtBx").value == ""));