JSFiddle - React, Tailwind, and code Playground
HTML
<input type="checkbox" checked /> Test
<p>Checkbox status: <span id="status"></span></p>
JavaScript
$('#status').text( $('input:checkbox').attr('checked') === "" );
<input type="checkbox" checked /> Test
<p>Checkbox status: <span id="status"></span></p>
$('#status').text( $('input:checkbox').attr('checked') === "" );