Why Doesn't `table > tr > td` Select Table Cells as Expected in CSS?

tr > td` Select Table Cells as Expected in CSS? " />

Understanding the Limitations of the Child Selector for Table Structures

In HTML document structure, the relationship between table > tr > td elements is often assumed to be a parent-child hierarchy. However, when using CSS selectors, it's crucial to understand why the child selector (>) behaves unexpectedly for this structure.

The > tr > td selector may seem like it should select td elements that are immediate descendants of tr elements, which in turn are direct descendants of the table element. However, in the actual HTML structure, browsers implicitly introduce an additional tbody element.

This means that the actual hierarchy looks like this:

table > tbody > tr > td

As a result, the selector table > tr > td will not work because tr elements are not direct children of the table element. Instead, they are children of the tbody element.

To correctly select td elements in this scenario, you should use the following selector:

table > tbody > tr > td

Demonstration:

In the provided Fiddle [Descendant selector](http://jsfiddle.net/brLee/1/), the tr > td selector works as expected, selecting all td elements within the tr elements. This is because the descendant selector (>) selects all descendants of the specified element, including those that are indirectly related.

In contrast, the provided Fiddle [Child selector](http://jsfiddle.net/brLee/), which uses table > tr > td, does not select any td elements because the tr element is not a direct child of the table element.

Browser Behavior:

In HTML documents, the implicit addition of the tbody element is a default behavior of browsers to ensure proper rendering of tables. However, in XHTML documents served as application/xhtml xml, this implicit addition does not occur. As such, using the child selector (>) for table > tr > td in XHTML documents will work correctly.

The above is the detailed content of Why Doesn't `table > tr > td` Select Table Cells as Expected in CSS?. For more information, please follow other related articles on the PHP Chinese website!