From some official PHP documentation:
Returns the name of the class of whichobjectis an instance. ReturnsFALSEifobjectis not an object.
On the surface, it's a cute seemingly-contradiction. Sure, the context might clear things up a bit, and you might conclude it was just an unfortunate choice of words. But really, think about that last sentence for a moment.
ADDENDUM: Yes, I was just looking for ways to make snarky remarks on PHP, which makes more sense when you're an "everything is an object" zealot.