HTML5

4.9.10 The th element

Categories:

None.

Contexts in which this element can be used:

As a child of a tr element.

Content model:

Flow content, but with no header, footer, sectioning content, or heading content descendants.

Content attributes:

Global attributes

colspan

rowspan

headers

scope

DOM interface:

interface HTMLTableHeaderCellElement : HTMLTableCellElement {
           attribute DOMString scope;
};

The th element represents a header cell in a table.

The th element may have a scope content attribute specified. The scope attribute is an enumerated attribute with five states, four of which have explicit keywords:

The row keyword, which maps to the row state

The row state means the header cell applies to some of the subsequent cells in the same row(s).

The col keyword, which maps to the column state

The column state means the header cell applies to some of the subsequent cells in the same column(s).

The rowgroup keyword, which maps to the row group state

The row group state means the header cell applies to all the remaining cells in the row group. A th element's scope attribute must not be in the row group state if the element is not anchored in a row group.

The colgroup keyword, which maps to the column group state

The column group state means the header cell applies to all the remaining cells in the column group. A th element's scope attribute must not be in the column group state if the element is not anchored in a column group.

The auto state

The auto state makes the header cell apply to a set of cells selected based on context.

The scope attribute's missing value default is the auto state.

The following example shows how the scope attribute's rowgroup value affects which data cells a header cell applies to.

Here is a markup fragment showing a table:

<table>
 <thead>
  <tr> <th> ID <th> Measurement <th> Average <th> Maximum
 <tbody>
  <tr> <td> <th scope=rowgroup> Cats <td> <td>
  <tr> <td> 93 <th scope=row> Legs <td> 3.5 <td> 4
  <tr> <td> 10 <th scope=row> Tails <td> 1 <td> 1
 <tbody>
  <tr> <td> <th scope=rowgroup> English speakers <td> <td>
  <tr> <td> 32 <th scope=row> Legs <td> 2.67 <td> 4
  <tr> <td> 35 <th scope=row> Tails <td> 0.33 <td> 1
</table>

This would result in the following table:

ID	Measurement	Average	Maximum
	Cats
93	Legs	3.5	4
10	Tails	1	1
	English speakers
32	Legs	2.67	4
35	Tails	0.33	1

The headers in the first row all apply directly down to the rows in their column.

The headers with the explicit scope attributes apply to all the cells in their row group other than the cells in the first column.

The remaining headers apply just to the cells to the right of them.