JSFiddle - React, Tailwind, and code Playground

HTML

<html>
<body>

<div id="parent" style="border:2px solid red; width:300px;height:200px">
    text of parent
    <div id="child1" style="border:1px solid green; width:200px;height:80px">Text of child1</div>
    <div id="child2" style="border:1px solid blue; width:200px;height:80px">Text of child2</div>
</div>

</body>
</html>

JavaScript

var div = document.getElementById("parent");
div.firstChild.data = "";