Question

As specified in the W3 specification for Tables:

Table rows may be grouped into a table head, table foot, and one or
more table body sections, using the THEAD, TFOOT and TBODY elements,
respectively. This division enables user agents to support scrolling
of table bodies independently of the table head and foot.

I created the following example, but it doesn’t work.

HTML:

<table>
    <thead>
        <tr>
            <td>Problem</td>
            <td>Solution</td>
        </tr>
    </thead>
    <tbody>
    </tbody>
</table>

JS:

$(function() {
    for (var i = 0; i < 20; i++) {
        var a = Math.floor(10 * Math.random());
        var b = Math.floor(10 * Math.random());
        var row = $("<tr>").append($("<td>").html(a + " + " + b + " ="))
                           .append($("<td>").html(a + b));
        $("tbody").append(row);
    }
});

CSS:

table {
    background-color: #aaa;
}
tbody {
    background-color: #ddd;
    height: 100px;
    overflow: auto;
}
td {
    padding: 3px 10px;
}

Answer 1

The missing part is:

thead, tbody {
    display: block;
}

Demo