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When would you use interface vs superclass?
Thus, if a class already has a different superclass, it can implement an interface, but it cannot extend another abstract class. Therefore interfaces are a more flexible mechanism for exposing a common interface. If you need to separate an interface from its implementation, use an interface.
Does subclass need to implement interface?
No. An interface defines how a class should look like (as a bare minimum). Whether you implement this in a base class or in the lowest subclass doesn’t matter.
Should I use @override when implementing interface?
You should use @Override whenever possible. It prevents simple mistakes from being made.
Can you override an interface?
‘override’ is not allowed when implementing an interface method. We could have an ‘implements’ attribute to mark methods doing the latter, but that seems like overkill since you’ll get a “method not implemented” error or type error if you don’t get the name and type of the implementing method right.
Can a class implement an interface in another class?
The classes that implement a interface need not be descendant from the same parent class but other classes that want to ensure a contract exists, can call the same methods on objects of all classes that implement the interface. Interface ensures that this contract is available.
Can a superclass abstract an interface in Java?
You may choose to implement the interface in the superclass but make the superclass abstract if it does not have enough details to implement the interface methods. This way you can enforce the subclasses to adhere to the interface contract.
Can a subclass inherit an interface from an abstract class?
Abstract classes can allow to implement the methods from an interface they implement to be implemented in sub classes by marking the definition as abstract. And as you can see in the main method, both defining the object as BaseClass or SomeInterface works and makes no difference. Thanks for contributing an answer to Stack Overflow!
How to inherit interface from superclass in Java?
The superclass is called store. The subclass is called retail, it should receive the superclass’s constructor, the number of items sold, unit price, and sale price should be array arguments. This class implements two methods that are defined at interface.