JSFiddle - React, Tailwind, and code Playground

by mich

HTML

<div>
    <input type="checkbox" name="foo1">
    <input type="checkbox" name="foo2">
    <input type="checkbox" name="foo3">
    <input type="checkbox" name="foo4">
</div>
<div id="count">0</div>

JavaScript

$('input[type=checkbox]').click(function(event) {   
    var count = $(this).parent().find('input[type=checkbox]:checked').length;
    $('#count').html(count);
                                                     
});