JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr><td><button class='a'>1</button></td></tr>
    <tr><td><button class='a'>2</button></td></tr>
    <tr><td><button class='a'>3</button></td></tr>
    <tr><td><button class='a'>4</button></td></tr>
    <tr><td><button class='a'>5</button></td></tr>
</table>

JavaScript

var list = document.querySelectorAll(".a");
for(var i=0; i<list.length; i++) {
    list[i].onclick = function() {
        var row = this.parentNode.parentNode,
            rows = row.parentNode.querySelectorAll("tr"),
            index = 0;
        for( var r=0; r<rows.length; r++) {
            console.log(rows[r]);
            if(row==rows[r]) {
                index = r;
                break;
            }
        }
        console.log(index);
        row.parentNode.removeChild( row );
    };    
}