JSFiddle - React, Tailwind, and code Playground

HTML

<div style="background-color:yellow;display:block;" id="elem1">1</div>
<br>
<div style="background-color:red;display:block;" id="elem2">2</div>
<br>
<div style="background-color:blue;display:block;" id="elem3">3</div>
<br>
<div style="background-color:green;display:block;" id="elem4">4</div>
<br>
<div style="background-color:orange;display:block;" id="elem5">5</div>
<br>
<div style="background-color:pink;display:block;" id="elem6">6</div>

JavaScript

var someString = "START";

setListener();

function setListener(message) {
    message = message || someString;
    document.getElementById('elem1').onclick = function(){
        alert(message);
    };
}

var someString = "END";