JSFiddle - React, Tailwind, and code Playground

HTML

<div id="u">
    <span><input type="submit" value="1a"></span>
    <span></span>
    <span><input type="submit" value="2a"></span>
    <span><input type="submit" value="3a"></span>
</div>

JavaScript

$("input[type='submit']").click(function(){
    alert($(this).index());
});