Header files

Header files should contain #includes, #defines, functions definitions, classes declarations, structures and some other things

If you declare variables in a header file and include it in two or more modules (what you will certainly do on bigger projects) you will get linkin errors because it would be the same as declaring the same variable in every module of the project

If you want to declare constant variables in it, #define them because defines are not actualy variables, they are substituted by the compiler when you build your project...

Ok?

quote:

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Original post by RaptorZero
If you declare variables in a header file and include it in two or more modules (what you will certainly do on bigger projects) you will get linkin errors because it would be the same as declaring the same variable in every module of the project

If you want to declare constant variables in it, #define them because defines are not actualy variables, they are substituted by the compiler when you build your project...

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consts are not subject to this restriction. You can put const variables in a header file without the linker complaining.

And const > #define.



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Clicky
You can use constants in headers (I think):

int const ARBITRARY_INTEGER = 5;
float const PI = 3.141592654f;
char const* const VERSION = "3.7 alpha";   // Note there are TWO ''const''s
 

Why is const > #define?

What are the advantages?

const allows the compiler to perform type-checking. Which is a great thing.