To solve just about any problem in coding, you need to be specific. So yes, take the first example you sort of give. Post the code for the class you created including the functions where you use it AND then post the error messages that you receive when you try to run it.

Nearly all problems in coding are solvable this way. Basically, this is the same message I received from a FORTRAN consultant in 1963 when I encountered problems in my first program. (Minus the profanity and screaming.).

Gary