Difference between Enum and Define Statements

Question

What's the difference between using a define statement and an enum statement in C/C++ (and is there any difference when using them with either C or C++)?

For example, when should one use

enum {BUFFER = 1234};  

over

#define BUFFER 1234    

Answer 1

enum defines a syntactical element.

#define is a pre-preprocessor directive, executed before the compiler sees the code, and therefore is not a language element of C itself.

Generally enums are preferred as they are type-safe and more easily discoverable. Defines are harder to locate and can have complex behavior, for example one piece of code can redefine a #define made by another. This can be hard to track down.

Answer 2

#define statements are handled by the pre-processor before the compiler gets to see the code so it's basically a text substitution (it's actually a little more intelligent with the use of parameters and such).

Enumerations are part of the C language itself and have the following advantages.

1/ They may have type and the compiler can type-check them.

2/ Since they are available to the compiler, symbol information on them can be passed through to the debugger, making debugging easier.