JSFiddle - React, Tailwind, and code Playground

HTML

<input type='button' value='0'/>
<input type='button' value='0'/>
<input type='button' value='0'/>
<input type='button' value='0'/>
<input type='button' value='0'/>

JavaScript

var ins=document.getElementsByTagName('input');

for (var i=0;i<ins.length;i++){
    ins[i].setAttribute('data-myvalue',i);
    ins[i].addEventListener('click',
               function(){alert(this.getAttribute('data-myvalue'));});
}