M8 Abstraction in Object Oriented Programming

Flashcards on abstraction, abstract classes, and interfaces in Java.

Abstraction

A way of separating the implementation of an interface and one of a design motif of OOP such as encapsulation, Inheritance, Polymorphism, Class, and Object.

Abstraction in Java

Achieved by using interfaces or abstract classes.

Extend Keyword

Used for an abstract class to implement an abstract method with concrete behavior.

Implement Keyword

Used for an interface to implement an abstract method with concrete behavior.

Abstract Class Method Type

Both abstract and non-abstract

Interface Method Type

Abstract method

Abstract Class Method Implementation

Some methods are implemented, while some methods do not implemented but could be override

Interface Method Implementation

All methods are implemented

Abstract Class Inheritance

Single inheritance (A class can be inherit from a single class)

Interface Inheritance

Support multiple inheritance

Abstract Class Representation

An abstract class represents a type of object

Interface Representation

Interface represents a set of behaviors

Abstract Class Access Modifiers

Public, protected, and private are used in abstract class for their methods and properties

Interface Access Modifiers

Only public modifier with methods

Abstract Class Variables

Abstract class can have attributes

Interface Variables

Interface don’t have attributes

Feature of Abstract Class

It can not be instantiated

Feature of Interface

It support polymorphism and multi inheritance

Final Keyword

Immutable objects, it means once an object is created, it cannot be modified

The final keyword

Prevents child classes from overriding a method.