Mell How will you choose whether to use an abstract class or an interface?
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.
When should I use abstract class?
Abstract Classes are a good fit if you want to provide implementation details to your children but don’t want to allow an instance of your class to be directly instantiated (which allows you to partially define a class). If you want to simply define a contract for Objects to follow, then use an Interface.
Where do we use abstract class and interface in real life scenario?
So, abstract classes can be used to consolidate and share functionality, while interfaces can be used to specify what the common functionality that will be shared between different instances will be, without actually building that functionality for them. Both can help you make your code smaller, just in different ways.
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’s different between interface and abstract class?
An abstract class is object orientated while interface is function oriented. When you want API to stay constant for a while then you choose interface over abstract class. Multiple inheritances could be gained by implying multiple interfaces. While in abstract class, you cannot get multiple inheritances.
What is the advantage of interface over abstract classes?
The main advantages of interface over abstract class is to overcome the occurrence of diamond problem and achieve multiple inheritance. In java there is no solution provided for diamond problem using classes.For this reason multiple inheritance is block using classes in java.
Can you implement an interface in abstract class?
In Java, an abstract class can implement an interface, and not provide implementations of all of the interface’s methods. It is the responsibility of the first concrete class that has that abstract class as an ancestor to implement all of the methods in the interface.
When do we go for abstract and interface?
Both abstract classes and interfaces are used when there is a difference in behaviour among the sub-types extending the abstract class or implementing the interface.