The difference between C + + virtual function and pure virtual function

Both virtual and pure virtual functions can be overridden in subclasses, except:

In general, pure virtual functions are only defined without implementation, for example:

virtual bool Init (void) = 0;

The general virtual function must have the implementation of the part of the code, otherwise there will be a function undefined error

Secondly:

As long as there is a pure virtual function in the class, then he is an abstract class, it is not possible to generate objects, if it is a virtual function, then can be defined to generate concrete objects.

The difference between C + + virtual function and pure virtual function