JSFiddle - React, Tailwind, and code Playground

HTML

<table id="otherTable"></table>
<table id="myTable"></table>

CSS

.none {
    display: none;
}
.showRow {
    display: table-row;
}

JavaScript

for (var i = 0; i < 10; i++) {
    var table = document.getElementById("myTable"),
        row = table.insertRow(table.rows.length),
        cell0 = row.insertCell(0),
        cell1 = row.insertCell(1),
        cell2 = row.insertCell(2);

    var dirText = document.createTextNode('2');
    cell0.appendChild(dirText);

    var filenameText = document.createTextNode('1');
    cell1.appendChild(filenameText);
}

for (var l = 0; l < document.getElementById('myTable').rows.length; l++) {
    document.getElementById('myTable').rows[l].className = 'none';
}

document.getElementById('myTable').rows[2].className = 'showRow';
alert(document.querySelector('#myTable tr.showRow'));