C++ nil vs NULL

Question

OK, I have some C++ code in a header that is declared like this:

void StreamOut(FxStream *stream,const FxChar *name = nil);

and I get: error:

'nil' was not declared in this scope

nil is a pascal thing, correct?

Should I be using NULL?

I thought they were both the same or at least Zero, no?

Answer 1

In C++ you need to use NULL, 0, or in some brand new compilers nullptr. The use of NULL vs. 0 can be a bit of a debate in some circles but IMHO, NULL is the more popular use over 0.

Answer 2

nil does not exist in standard C++. Use NULL instead.

Answer 3

Yes. It's NULL in C and C++, while it's nil in Objective-C.

Each language has its own identifier for no object. In C the standard library, NULL is a typedef of ((void *)0). In C++ the standard library, NULL is a typedef of 0 or 0L.

However IMHO, you should never use 0 in place of NULL, as it helps the readability of the code, just like having constant variables in your code: without using NULL, the value 0 is used for null pointers as well as base index value in loops as well as counts/sizes for empty lists, it makes it harder to know which one is which. Also, it's easier to grep for and such.

Answer 4

0 is the recommended and common style for C++