Question

How do I define a function inside of a class using C++?

Answer 1

There are 2 answers:

1) Combining both the declaration and the definition:

class C
{
public:
  //declaration and definition of f
  void f()
  {
  }

};

2) Separating the declaration and the definition:

class C
{
public:
  //declaration of f
  void f();
};

//definition of f
void C::f()
{
}

Typically in option #2 you would separate the declaration into a header file and the definition inside a source file.