JSFiddle - React, Tailwind, and code Playground

HTML

<div class='red'>xxx</div>

JavaScript

function click(red){
    var source = document.getElementsByClassName(red);
		for (i = 0; i < source.length; i++) {
            source[i].addEventListener('click', err, false);
		}
    function err() { 
    var x = 0;
    }
}

if (click('red')) {
	alert('rrr');
}