JSFiddle - React, Tailwind, and code Playground

HTML

<div>
    <input type="checkbox" class='gender' id="male">male</input>
    <input type="checkbox" class='gender' id="female">female</input>
</div>
<button class="validate">Validate</button>

JavaScript

$(function() {
  $('.validate').click(function(event) {     
     var checkedCount = ($('input[class="gender"]:checked').length))        
  })   
});