Why would you use an interface?
You use an interface to define a protocol of behavior that can be implemented by any class anywhere in the class hierarchy. Interfaces are useful for the following: Capturing similarities among unrelated classes without artificially forcing a class relationship.
Why we use interface and how we can implement it?
The interface allows sending a message to an object without concerning which classes it belongs. Class needs to provide functionality for the methods declared in the interface. An interface cannot implement another Interface. It has to extend another interface if needed.
Why do you need to implement all the methods of an interface?
Yes, it is mandatory to implement all the methods in a class that implements an interface until and unless that class is declared as an abstract class. Declare the class as an abstract class, as a result, forces you to subclass the class (and implement the missing methods) before you can create any objects.
Is it necessary to implement all methods of abstract class?
It’s not necessary for an abstract class to have abstract method. The subclass of abstract class in java must implement all the abstract methods unless the subclass is also an abstract class. All the methods in an interface are implicitly abstract unless the interface methods are static or default.
What is purpose of abstract class?
The short answer: An abstract class allows you to create functionality that subclasses can implement or override. An interface only allows you to define functionality, not implement it. And whereas a class can extend only one abstract class, it can take advantage of multiple interfaces.
What is difference between abstract class and interface with real time example?
Abstract classes can have methods with implementation whereas interface provides absolute abstraction and can’t have any method implementations. Abstract classes can have constructors but interfaces can’t have constructors. Abstract class have all the features of a normal java class except that we can’t instantiate it.
What is interface with real time example?
An interface in java it has static constants and abstract methods only. for real time example – it is 100% abstraction. example is, Comparator Interface. If a class implements this interface, then it can be used to sort a collection.
What is the benefit of abstract class can you give any real system example?
One of the major benefits of abstract classes is that you can reuse code without having to retype it. That has a plethora of benefits, such as reducing bugs and making coding faster. A concrete example of an abstract class would be a class called Animal.
What is an abstract class explain with an example?
A class that is declared using “abstract” keyword is known as abstract class. It can have abstract methods(methods without body) as well as concrete methods (regular methods with body). A normal class(non-abstract class) cannot have abstract methods.
What is the real use of interface?
Interface is great to declare Type, they promote code reusability, and they are the real driver of polymorphism in Java. Interface also allows multiple inheritance in Java, which makes it possible for a class to become Canvas, as well as EventListener, which is used to draw graphics as well as to to process events.
What are the interfaces explain with an example?
Interfaces in Object Oriented Programming Languages. An interface is a programming structure/syntax that allows the computer to enforce certain properties on an object (class). For example, say we have a car class and a scooter class and a truck class. Each of these three classes should have a start_engine() action.
Which is the advantage of encapsulation?
The main advantage of using encapsulation is the security of the data. Benefits of encapsulation include: Encapsulation protects an object from unwanted access by clients. Encapsulation allows access to a level without revealing the complex details below that level.
What is abstraction and encapsulation give real life example?
For an example of encapsulation i can think of the interaction between a user and a mobile phone. The user does not need to know the internal working of the mobile phone to operate, so this is called abstraction.
What is abstraction Can you give an example?
Abstraction is a technique of hiding unnecessary details from the user. The user is only given access to the details that are relevant. Vehicle operations or ATM operations are classic examples of abstractions in the real world.
What is an example of abstraction?
The definition of abstraction refers to the concept of being preoccupied or absent minded. An example of abstraction is when your finances may dominate your thoughts and prevent you from focusing on other ideas or tasks. An abstract work of art.