JSFiddle - React, Tailwind, and code Playground

HTML

<div class="source">s1</div>
<div class="source">s2</div>
<div class="source">s3</div>
<input type="button" onclick="toggle('source')" name="toggle_button" value="toggle" />

JavaScript

function toggle(class) {
   var el = document.getElementsByClassName(class);
   for(var i = 0; i < el.length; i++){
              (el[i].style.display == 'none')
              ? el[i].style.display = ''
              : el[i].style.display = 'none';
   }
}