C++ and initializing constants in separator files

Question

I have a header file which declares the prototype for the constructor. In a separate file I have the constructor and all other methods declared outside the class. The constructor should instate constants also.

How do I define the prototype, with the : constant_name(constant arg), etc.. or without and just write it in full form in the external file?

Answer 1

"How do I define the prototype? with the constant_name(constant arg) ..."
Are you asking how to define a constant, a function with constant argument, a class' constructor, or something else? it's not clear as it is now ...