Question: Can We Write Main Method In Abstract Class?

Can abstract class have constructor C++?

An abstract class can have constructor similar to normal class implementation.

In the case of the destructor, we can declare a pure virtual destructor..

Can we use final keyword in abstract class?

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.

Can we inherit abstract class?

An abstract class defines the identity of a class. An interface can inherit multiple interfaces but cannot inherit a class. An abstract class can inherit a class and multiple interfaces. … An abstract class can declare constructors and destructors.

Can we have concrete methods in abstract class?

Abstract class can have both an abstract as well as concrete methods. A concrete class can only have concrete methods. Even a single abstract method makes the class abstract. Abstract class can not be instantiated using new keyword.

Can we write static method in abstract class?

Can an abstract class have static methods? Yes, abstract class can have Static Methods. The reason for this is Static methods do not work on the instance of the class, they are directly associated with the class itself.

What is difference between abstract class and interface?

Abstract class can inherit another class using extends keyword and implement an interface. Interface can inherit only an inteface. Abstract class can be inherited using extends keyword. Interface can only be implemented using implements keyword.

How can we convert class into abstract class?

Right-click and choose Refactor | Convert Interface to Abstract Class in the context menu. Choose ReSharper | Refactor | Convert | Method to Indexer… in the main menu.

Can we define a method in abstract class?

Abstract classes are similar to interfaces. You cannot instantiate them, and they may contain a mix of methods declared with or without an implementation. However, with abstract classes, you can declare fields that are not static and final, and define public, protected, and private concrete methods.

Can we override static method?

Can we override a static method? No, we cannot override static methods because method overriding is based on dynamic binding at runtime and the static methods are bonded using static binding at compile time. So, we cannot override static methods.

Can abstract class have constructor?

Yes! Abstract classes can have constructors! Yes, when we define a class to be an Abstract Class it cannot be instantiated but that does not mean an Abstract class cannot have a constructor. Each abstract class must have a concrete subclass which will implement the abstract methods of that abstract class.

Can we inherit one abstract class to another abstract class?

The only time a class cannot inherit from another is when the class you wish to inherit from is sealed or has private constructors only. Yes you can inherit an abstract class from another abstract class.

Why we Cannot override static method?

Static methods cannot be overridden because they are not dispatched on the object instance at runtime. The compiler decides which method gets called. Static methods can be overloaded (meaning that you can have the same method name for several methods as long as they have different parameter types).

Which method Cannot be overridden?

A method declared final cannot be overridden. A method declared static cannot be overridden but can be re-declared. If a method cannot be inherited, then it cannot be overridden. A subclass within the same package as the instance’s superclass can override any superclass method that is not declared private or final.

Can we have main method in interface?

Answer : Yes, we can provide different implementation of main() declared in an interface and classes implementing that interface by overriding method and can overload static main method if defined in an interface. Some more information regarding interface changes in Java 8.

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.