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Can an abstract class have empty methods?
abstract method bodies must be empty (no curly braces)
What is use of empty abstract class?
2. The key is that you can extend from only one abstract class, while you can implement more interfaces. Apparently the “empty abstract class” design desicion was made so that it prevents the implementing class from extending from another classes. If it was me I’d let it go, otherwise it might break.
What is an empty method?
empty() method in Java is used to check whether a stack is empty or not. The method is of boolean type and returns true if the stack is empty else false. Return Value: The method returns boolean true if the stack is empty else it returns false.
Can a method body be empty?
3 Answers. Although it is certainly OK to have an empty method that does nothing, you should evaluate its alternative – an empty method that is missing entirely, i.e. an abstract method.
Is abstract class bad?
No, They are not obsolete. In fact, there is an obscure but fundamental difference between Abstract Classes/Methods and Interfaces. if the set of classes in which one of these has to be used have a common behaviour that they share (related classes, i mean), then go for Abstract classes/methods.
Can a function body be empty?
But it can have it’s own function body though it doesn’t expect any argument & return nothing. Yes, a function that does not accept any arguments, it does not return anything, and does nothing in its body.
Is empty in C++?
The list::empty() is a built-in function in C++ STL is used to check whether a particular list container is empty or not. Return Value: The return type of this function is boolean. It returns True is the size of the list container is zero otherwise it returns False.
Which is an example of an empty method body?
If you are really sure that an empty method body is okay for most sub-classes, you could follow the example of Swing listeners (e.g. WindowListener / WindowAdapter ): Make the methods in your Foo class abstract, but provide an abstract class called FooAdapter extending Foo, which implements that methods with empty bodies.
Which is better, an empty method or an abstract method?
Having an “empty” method is fine. But in order to be sure, that it will be implemented where it is really needed, consider throwing an exception by default from this method: I can’t help feeling like you have some architectural/design issues here, but without knowing more, I can’t say for sure.
Do you need an abstract class in Java 8?
Update: Of course, if you can use Java 8, you can write default methods in interfaces, hence an abstract class isn’t needed. I would declare as required by all classes. It is easy enough to leave an empty method stub in the sub class. I agree with IAbstract’s answer, but I want to expand upon it with my own 2 cents.
Why do children override the abstract base with an empty implementation?
In addition, providing an empty implementation in the abstract base would possibly lead to children believing there is, in fact, some default implementation that might actually do something. You might have children overriding the method with an empty implementation simply because they do not want anything done!