"This mostly is a credit to the phenomenal Reflection API that PHP offers. I must confess that I haven't used either Ruby or Python, but I would be initially doubtful to believe that they have as strong features in terms of reflection as PHP does... (correct me if I'm wrong)"

Just have to point out here that Ruby's reflection is pretty much its main "killer feature". Even something as simple as bar = foo.class.new() is enough to tell you that Ruby has some serious reflection built right into the language: asking for an instance's class doesn't give you the name of the class, it gives you the class itself, which you can use in a useful manner. PHP 6 is going to bring a lot of neat things, but I still don't see anything like that on the horizon.

PHP6 is going to clean things up a lot, and I really hope that it gets stable enough that I can actually use it in a production environment. Same experience with Ruby on Rails hype being more than it delivers, and I wouldn't want to use rails after the experiences I had with it.

But -- can't knock Ruby's reflection. Try it out. Don't use it in production, just try using ruby. Its simplicty makes it great for prototyping and working out an object model.

However, I truly agree to what Gordon said about how "you choose to make it". Yes, that's pretty much what I think about PHP programmers around me.

ps: Maybe I don't have as much authority to talk about PHP since web programming is just my hobby. But really, I've tried all famous/fancy ones and picked PHP at the end, so it is the language of my choice

isset() and empty() have very specific purposes that I actually recently wrote about, but I will admit that is_null() is a completely useless function. The reason it exists, however, is to maintain consistency with the other is_type() functions.