JSFiddle - React, Tailwind, and code Playground

HTML

<p>
<label>Original:</label><br>
<input type="text" id="val">
</p>

<p>
<label>Encoded:</label><br>
<input type="text" id="val-encoded">
</p>

<p>
<label>Decoded</label><br>
<input type="text" id="val-decoded">
</p>

JavaScript

var val = 'A & B > C';
$('#val').val(val);

var valEncoded = $('<div>').text(val).html();
$('#val-encoded').val(valEncoded);

var valDecoded = $('<div>').html(valEncoded).text();
$('#val-decoded').val(valDecoded);