Highlight PHP Source Code

The PHP language has two modes. It can either be used as a standalone language (pure mode) or it can be mixed with HTML (mixed mode) by putting it inside PHP tags (a form that resembles an XML processing instruction). This presents some challenges for the syntax highlighter.

If the code in the source block is pure PHP, you should use the language tag php. For example:

If the PHP source is mixed with HTML, you should either use the language tag html+php, as shown here:

Or you should use the language tag php and set the mixed option on the source block, as shown here:

Under the covers, the syntax highlighter is configured to assume an implicit start PHP tag is present when the language tag is php. Both the mixed option and the language tag html+php disable this setting.