Can constructor be abstract?

Can constructor be abstract?

You can’t have an abstract constructor, as abstract means you need to provide the implementation for that at some point of time in your subclass. But you cannot override constructor. There will be no point in having an abstract constructor : Since the constructor needs to be of the same name as of class.

Is it possible to create an object for the abstract class?

No, we can’t create an object of an abstract class. But we can create a reference variable of an abstract class. The reference variable is used to refer to the objects of derived classes (subclasses of abstract class).

Can we make abstract class as final?

Yes, there may be “final” methods in “abstract” class. But, any “abstract” method in the class can’t be declared final. It will give “illegal combination of modifiers: abstract and final” error. Here is the working example of the implementation.

Why does an abstract class need a constructor?

Purpose of constructor is abstract classes may contain fields and sometimes they need to be initialized somehow by using constructor. This chaining of constructors is one of the reasons abstract class can have constructors in Java. Abstract class has fields X and Y.

Does a subclass need to have a constructor?

Because a constructor initializes an instance of a class, they are never inherited; however, the subclass must call a superclass constructor as it is an extension of a superclass object. This can be done in either of the two ways shown below. Consider the following class:

Is there a way to instantiate abstract class?

An abstract class cannot be instantiated.

  • An abstract class may contain abstract methods and accessors.
  • It is not possible to modify an abstract class with the sealed modifier because the two modifiers have opposite meanings.

    Can abstract class have data members?

    An abstract class can have data members. When an abstract class have data members then it become necessary for all derived classes to have those data members.