"Why can't you instantiate an interface or an abstract class?"
The short answer: because that's how they are defined.
Instantiate - to create one instance of a class. The newly created object is a "kind of" the class.
Interface - a declaration of methods that are expected of a class. If the class declares they implement the interface, it must provide implementations for all the methods declared by the interface.
Abstract Class - a class that cannot be instantiated. Often it will include one or more methods that are also declared abstract and must be implemented by subclasses for the subclass to be concrete (opposite of abstract), and therefore able to be instantiated. Does not have to include abstract methods; the documentation may otherwise specify what is required of a valid concrete subclass.
Bill Shirley - bshirley - frazerbilt.com
if (Posts < 30) you.read( JavaRanchFAQ);
subject: Why we can't create object to ABSTRACT & INTERFACE classes?