Question

Possible Duplicate:
“static const” vs “#define” in c

I am going through the K&R book and this question came up. How to best decide whether something should be its own variable or be defined as a symbolic constant?

Suppose we’re dealing with const int myNumber = 12; , which also can be #define MY_NUMBER 12 is there a rule of thumb one should follow when deciding which whether a variable needs to be created or symbolic constant used?

Answer 1

If you’re hard-coding a constant like “2” … then it’s a candidate for symbolic parameter.

ADDENDUM:

You changed the question 🙂

Q: I am going through the K&R book and this question came up. How to
best decide whether something should be its own variable or be defined
as a symbolic parameter?

A: “Magic numbers” are bad. Use “#define SOME_MEANINGFUL_NAME 2” in preference to “2”.

Q: Suppose were dealing with const int myNumber = 12; , which also can
be #define MY_NUMBER 12 is there a rule of thumb one should follow
when deciding which approach to take here?

A: If you’re using C++ or C#, then you should probably use “const” in favor of “#define”.