Example in C++
class Abstract
{
public:
virtual void MyVirtualMethod() = 0;
};
class Concrete : public Abstract
{
public:
void MyVirtualMethod()
{
//do something
}
};
An object of class Abstract can not be created because the function MyVirtualMethod has not been defined ( the =0 is C++ syntax for the a pure virtual function, a function that must be part of any (derived) class but is not defined in the base class. The Concrete class is a concrete class because it's functions (in this case, only one function) have been declared and implemented.
See also
