JSFiddle - React, Tailwind, and code Playground

HTML

<table>
    <tr>
        <td>checkbox 1<input type="checkbox" id="ck1" name="ck" value="check1" /></td>
        <td>checkbox 2<input type="checkbox" id="ck2" name="ck" value="check2" /></td>
        <td>checkbox 3<input type="checkbox" id="ck3" name="ck" value="check3" /></td>
    </tr>
</table>
<div id="trace"></div>

CSS

td { padding: 10px; }

JavaScript

var x = document.getElementById('ck1').value;
document.getElementById('trace').innerHTML = "by id: " + x;

var y = document.getElementsByName('ck');
for (var i = 0; i < y.length; i++) {
    document.getElementById('trace').innerHTML += "<br />" + y[i].value;
}