Dec 16, 2009 · When inheriting an abstract class, a concrete child class must define the abstract methods, whereas an abstract class can extend another abstract class and abstract methods …

For abstract methods you have to explicibly state it, yes. For virtual methods it is more complicated. If you don't state the override keyword there, the original method will become …

Why can't Java classes have abstract fields like they can with abstract methods? For example: I have two classes that extend the same abstract base class. These two classes each have a …

Consider an example (which compiles in java) public abstract interface Interface { public void interfacing (); public abstract boolean interfacing (boolean really); } Why is it necessary for...

Nov 4, 2008 · The same case applies to abstract classes. Though we cannot create an object of an abstract class, when we create an object of a class which is concrete and subclass of the …

Dec 6, 2011 · The abstract class is going to be responsible for getting the input, converting it to a long (for instance) and combining that value with the previous value in some way -- that "some …

Dec 23, 2016 · Of course you can create an instance of a concrete class that inherits the abstract class, and such an instance can also be said to be an instance of the abstract class.

Abstract classes/methods are generally used when a class provides some high level functionality but leaves out certain details to be implemented by derived classes.

Feb 20, 2015 · Declaring a method abstract means that subclasses have to provide an implementation for that method. The two are separate concepts, though obviously you can't …

Apr 8, 2011 · Why is it possible to write constructor for an abstract class in C#? As far as I know we can't instantiate an abstract class.. so what is it for? You can't instantiate the class, right?