Type of #define variables

Question

If I have:

#define MAXLINE    5000

What type is MAXLINE understood to be? Should I assume it is an int? Can I test it somehow?

Answer 1

It has no type. It's just a token which the preprocessor will put into the source code before passing the code to the compiler. You can do this (ridiculous) thing to declare a variable called x5000:

#define APPEND(x,y) x ## y

int main() {
        int APPEND(x,5000);
        x5000 = 3;
}

The preprocessor turns that into this before passing it the compiler proper:

int main() {
        int x5000;
        x5000 = 3;
}

So, just because you see 5000 in a macro, it doesn't mean it needs to be numeric in any way.