Refresher/SDLC/Abstract and Interface


Abstract and Interface    
 Abstract class (in C++, pure virtual method): blueprint for a class without any implementation and thus cannot be instantiated
 Abstract class methods: not all must be abstract, some can be concrete
 Abstract class required: when at least one of the methods in the class is abstract
 Abstract method: require non-abstract derived classes to provide their own implementation of this method
 Interface class: an abstract class with public abstract methods all of which must be implemented in the inherited classes
 Interface class methods: all must be abstract and public and thus accessibility modifiers not needed
 Multiple interfaces: can be inherited
 Namespace class: classes are declared inside a namespace