One thing I remember about Java back when I was working on enterprisey sorts of things is that for a language that supposedly has no pointers it sure seemed like we got a lot of NullPointerExceptions. NullPointerException was definitely the biggest cause of production bugs followed closely by ClassCastException. So if a language is purported to not have pointers why do they seem to be causing so many problems? Isn’t Java supposed to be better than C++ due to this lack of pointers?

The problem is that Java does have pointers. In fact everything that isn’t a primitive type is handled through pointers. There is no stack/heap dichotomy like there is in C/C++: you either have a primitive type that lives on the stack (or is part of a non-primitive object) or you have a non-primitive type that lives on the heap in the object store. These non-pointer pointers do have some advantages over their C/C++ cousins, the biggest being that dereferencing a null pointer doesn’t bring your whole program crashing down around you. Ah the advantages of a managed run-time where an invalid pointer dereference doesn’t have to treated as a possible attack and require the slaying of the perpetrator with extreme prejudice.

While it is nice that you can catch NullPointerExceptions, it would be nicer if people actually did it more than half the time. Like I said above: when I worked on enterprisey stuff NullPointerException was the single biggest cause of production problems. Now I don’t think that me or any of the people I was working with in said shop were morons. And it seemed like failure to account for the possibility of null pointers was one of the biggest problems we saw in programming tests we gave during interviews. I’d say that this is a product of the "java has no pointers" mentality but C/C++ programmers make their fair share of the same sort of error. Maybe certain languages that have done away with pointers altogether are on to something. Anyway, maybe keep this in mind the next time you’re bagging on C/C++ pointers compared to Java/C# keep in mind that you’re not really that far ahead of the game, a few steps maybe but not leaps and bounds.


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