Why cannot I compile these with Dev-C++?

Hello,

I've two examples, directly taken by my C++ manual, with no changes made by me.

You can find the main program file and the header file attached.

When I try to compile the project I have these errors:

Code:

  [Linker error] undefined reference to `Stock::Stock(char const*, int, double)'
  [Linker error] undefined reference to `Stock::Stock(char const*, int, double)' 
  [Linker error] undefined reference to `Stock::Stock(char const*, int, double)' 
  [Linker error] undefined reference to `Stock::Stock(char const*, int, double)' 
  [Linker error] undefined reference to `Stock::~Stock()' 
  [Linker error] undefined reference to `Stock::show() const' 
  [Linker error] undefined reference to `Stock::topval(Stock const&) const' 
  [Linker error] undefined reference to `Stock::show() const' 
  [Linker error] undefined reference to `Stock::~Stock()' 
  [Linker error] undefined reference to `Stock::~Stock()' 
  [Linker error] undefined reference to `Stock::~Stock()' 
  [Linker error] undefined reference to `Stock::~Stock()' 
  ld returned 1 exit status

Can you please help me?
Thank you!

You have to also include stock2.cpp in your project. Do you have that file?

Now got it and included. It works.

THANK YOU