Ilia put the slides of his talk on 06 Jun 2012 in Toronto named “Hidden Features
of PHP” online. He lists features, functions and extensions he thinks are hidden gems and shows examples of them. Slides are available at http://ilia.ws (PDF).
I scanned through and here is his selection as an apetizer:
Features and Functions
He starts with the __DIR__ constant followed by some other features like ternary operators, goto, encryption functions, double encoding and date parsing. Then stream_resolve_include_path (especially useful if you write your own wrappers), Session ini magic (with some focus on security), Better Hashing and some SPL FS Tricks (Yay, check those out, you need to know these).
That are a lot of slides for features, for example there’s one in between about
The mail.log and mail.add_x_header ini directive for example.
The other part of the slides are about extensions. Ilia showcases some of them:
igbinary – The awesome PHP Serializer you should use!
(I’m sure Ilia likes this one, I wonder if Facebook is d’accord with him.)