Variable or field declared void

I have a normal class where every function declaration which includes some arguments gives me the following error:

/Users/ralphdas/Documents/Open Frameworks/apps/SENSUS/Client/src/CreateOSCMessage.cpp:XX: error: variable or field ‘functionName’ declared void

I must have done something wrong in the .h file I guess. I had the same issue yesterday within some other class. It also shows up that the argument itself is not valid in this scope. I think it somehow acts like these function declarations are variables with the type void.

Must be an small mistake somehow… Check the classes below

I already fixed it.

I needed to type the argument types in the .cpp file as well

instead of:
void SomeClass::function( arg ){

void SomeClass::function( string arg ){