JSFiddle - React, Tailwind, and code Playground
HTML
<!DOCTYPE html>
<html>
<head>
<style>
</style>
</head>
<body>
<div>
<label> test input</label>
<input required />
</div>
<div>
<label>$('[required]').length</label>
<input id="a" />
</div>
<div>
<label>$('[required]').first().is("[required]")</label>
<input id="b" />
this one should be true
</div>
</body>
</html>
JavaScript
var d = $(document),
global = $('[required]').length,
first = $('[required]').first().is('[required]');
$('#a').val(global);
$('#b').val(first);