JSFiddle - React, Tailwind, and code Playground

HTML

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"></script>

<script>
    (function ($) {
        $.fn.isNot = function (selector) {
            return !this.is(selector);
        };
    })(jQuery);
</script>

<script>
    
    $(function() {
        $("#result").html( "Not checked: " + $("#result").isNot(":checked") );
    });
    
</script>

<div id="result"></div>