Definition
The <colgroup> HTML element is used to group and apply styling to a set of columns within an HTML table. It provides a way to define common properties or styles that should be applied to multiple columns simultaneously.
Here’s an example of how to use the <colgroup> element:
<table>
<colgroup>
<col style="background-color: lightblue;" />
<col style="background-color: lightgreen;" />
<col style="background-color: lightpink;" />
</colgroup>
<tr>
<td>Column 1</td>
<td>Column 2</td>
<td>Column 3</td>
</tr>
</table>
In this example, the <colgroup> element contains three <col> elements, each with a different background color. The <colgroup> is placed immediately after the opening <table> tag, and the <col> elements define the styling for the corresponding columns.
By grouping columns within a <colgroup>, you can apply common styles or attributes to multiple columns at once. This can include properties like background color, width, alignment, borders, and more.
The <colgroup> element helps improve the organization and maintainability of table styling by allowing you to define column properties in one place. It promotes consistency across multiple columns and provides a way to separate the presentation aspects of the table from its structural markup.
It’s important to note that the <colgroup> element is optional. If you don’t specify a <colgroup>, the table will still function correctly, and the columns will be styled based on default browser settings.
In summary, the <colgroup> element is used to group and apply styling to a set of columns within an HTML table. It allows you to define common properties or styles for multiple columns, promoting consistency and separating the presentation of the table from its structure.