JSFiddle - React, Tailwind, and code Playground

HTML

<div id="MyElement" onclick="fn()">

</div>

JavaScript

$.fn.attrThatBeginWith = function(begins){
	return [].slice.call(this.get(0).attributes).filter(function(attr) {
    	return attr && attr.name && attr.name.indexOf(begins) === 0
    });
};

var onAttributes = $("#MyElement").attrThatBeginWith("on");

console.log(onAttributes)