JSFiddle - React, Tailwind, and code Playground

HTML

<span class='text'>1</span>
<span class='text'>2</span>
<span class='text'>3</span>

CSS

.text{
    width:20px;
    height:20px;
    border:1px solid black;
}

JavaScript

var textSpans=document.querySelectorAll('span.text');
for (i=0;i<textSpans.length;i++)
{
    (function(v){
        textSpans[v].onclick=function() {alert(v);};  
    }(i));
}