The Standard PHP Library (SPL) is a powerful set of tools that are often overlooked. It is very common to see an SPL talk at conferences, but those talks usually just introduce each SPL class to the audience without giving some real world examples. I am going to show you a real world example on how to use SPL FilterIterator in an ecommerce website.

In my last post, I argued that the best way to start developing functional PHP applications was to code review some JavaScript projects.  I think this is a good place to start as most web developers have written some JavaScript at one point during their career.  I briefly mentioned that the array is pretty similar to the JavaScript object too.  However, if you start hacking away at PHP based on JavaScript's functional syntax, you will quickly run into some problems.

It has been said that all languages, over time, implement a dialect of lisp.  PHP appears to be no exception.