JSFiddle - React, Tailwind, and code Playground

by Chris Rebert

HTML

<div id="foo"></div>

JavaScript

var div = document.getElementById('foo');
var result = (div.addEventListener !== undefined);
var useCaptureOptional = false;
try {
    div.addEventListener('div', function () {});
    useCaptureOptional = true;
}
catch (e) {
    useCaptureOptional = false;
}
alert((result ? "PASS" : "FAIL") + "; useCapture optional: " + useCaptureOptional);