interface
Implementing two interfaces in a class with same method. Which interface method is overridden?
If a type implements two interfaces, and each interface define a method that has identical signature, then in effect there is only one method, and they are not distinguishable. If, say, the two methods have conflicting return types, then it will be a compilation error. This is the general rule of inheritance, method overriding, hiding, … Read more
Interface vs Base class
Let’s take your example of a Dog and a Cat class, and let’s illustrate using C#: Both a dog and a cat are animals, specifically, quadruped mammals (animals are waaay too general). Let us assume that you have an abstract class Mammal, for both of them: public abstract class Mammal This base class will probably … Read more
Abstract class vs Interface in Java
When To Use Interfaces An interface allows somebody to start from scratch to implement your interface or implement your interface in some other code whose original or primary purpose was quite different from your interface. To them, your interface is only incidental, something that have to add on to the their code to be able … Read more
How to use the Implements in Excel VBA
This is an esoteric OOP concept and there’s a little more you need to do and understand to use a custom collection of shapes. You may first want to go through this answer to get a general understanding of classes and interfaces in VBA. Follow the below instructions First open Notepad and copy-paste the below … Read more
Why are interface variables static and final by default?
From the Java interface design FAQ by Philip Shaw: Interface variables are static because Java interfaces cannot be instantiated in their own right; the value of the variable must be assigned in a static context in which no instance exists. The final modifier ensures the value assigned to the interface variable is a true constant … Read more
What is an interface in Java?
An interface is a special form of an abstract class which does not implement any methods. In Java, you create an interface like this: interface Interface { void interfaceMethod(); } Since the interface can’t implement any methods, it’s implied that the entire thing, including all the methods, are both public and abstract (abstract in Java … Read more
How to create interface between Fragment and adapter?
Make a new constructor and an instance variable: AdapterInterface buttonListener; public MyListAdapter (Context context, Cursor c, int flags, AdapterInterface buttonListener) { super(context,c,flags); this.buttonListener = buttonListener; } When the Adapter is made, the instance variable will be given the proper reference to hold. To call the Fragment from the click: public void onClick(View v) { buttonListener.buttonPressed(); … Read more
Implements vs extends: When to use? What’s the difference?
extends is for extending a class. implements is for implementing an interface The difference between an interface and a regular class is that in an interface you can not implement any of the declared methods. Only the class that “implements” the interface can implement the methods. The C++ equivalent of an interface would be an … Read more