Can we inherit abstract class?

An abstract class cannot be inherited by structures. It can contains constructors or destructors. It can implement functions with non-Abstract methods.

Can we inherit an abstract class in Java?

If a class is declared abstract, it cannot be instantiated. To use an abstract class, you have to inherit it from another class, provide implementations to the abstract methods in it. If you inherit an abstract class, you have to provide implementations to all the abstract methods in it.

Can we inherit abstract class and interface?

In C#, two classes (either abstract or concrete) cannot be inherited by the same derived class. It causes ambiguity in the derived class if both have the same method signature. We can do multiple inheritance in C# using interfaces.

Can we inherit more than one abstract class?

A class can inherit from multiple abstract classes.

Can abstract class have constructor?

Like any other classes in Java, abstract classes can have constructors even when they are only called from their concrete subclasses.

Java Programming Tutorial - 31 - Inheritance, Abstract Classes and Abstract Methods

Can we create object of abstract?

We cannot create objects of an abstract class. To implement features of an abstract class, we inherit subclasses from it and create objects of the subclass. A subclass must override all abstract methods of an abstract class.

Can we inherit static class in Java?

Static methods do not use any instance variables of any object of the class they are defined in. Static methods take all the data from parameters and compute something from those parameters, with no reference to variables. We can inherit static methods in Java.

Can a final class be inherited?

If a class is marked as final then no class can inherit any feature from the final class. You cannot extend a final class.

What is abstract inheritance?

The main difference between abstraction and inheritance is that abstraction allows hiding the internal details and displaying only the functionality to the users, while inheritance allows using properties and methods of an already existing class. Object-Oriented Programming (OOP) is a major programming paradigm.

Can static class be inherited?

Static classes are sealed and therefore cannot be inherited. They cannot inherit from any class except Object. Static classes cannot contain an instance constructor. However, they can contain a static constructor.

Can we declare a class as static?

So, Yes, you can declare a class static in Java, provided the class is inside a top-level class. Such clauses are also known as nested classes and they can be declared static, but if you are thinking to make a top-level class static in Java, then it's not allowed.

Can we inherit abstract class in C#?

Yes you can inherit or extend one abstract class to another abstract class but if the class is a sealed class or single ton class at that time only inheritance cant be applicable.

Can constructor be inherited?

Constructors are not members, so they are not inherited by subclasses, but the constructor of the superclass can be invoked from the subclass.

Can we override static method?

Overloading is the mechanism of binding the method call with the method body dynamically based on the parameters passed to the method call. Static methods are bonded at compile time using static binding. Therefore, we cannot override static methods in Java.

Can we inherit class having private constructor?

If a class has one or more private constructor and no public constructor then other classes are not allowed to create instance of this class; this means you can neither create the object of the class nor can it be inherited by other classes.

Can we inherit private method in Java?

No, we cannot override private or static methods in Java. Private methods in Java are not visible to any other class which limits their scope to the class in which they are declared.

Can constructor be static?

A static constructor is used to initialize any static data, or to perform a particular action that needs to be performed only once. It is called automatically before the first instance is created or any static members are referenced.

Can we create immutable class in Java?

Immutable class in java means that once an object is created, we cannot change its content. In Java, all the wrapper classes (like Integer, Boolean, Byte, Short) and String class is immutable. We can create our own immutable class as well.

Can interface be instantiated?

An interface can't be instantiated directly. Its members are implemented by any class or struct that implements the interface. A class or struct can implement multiple interfaces.

Can an abstract class be a subclass?

Abstract classes cannot be instantiated, but they can be subclassed. When an abstract class is subclassed, the subclass usually provides implementations for all of the abstract methods in its parent class. However, if it does not, then the subclass must also be declared abstract .

Can we create static method in interface?

Static methods in an interface since java8

Since Java8 you can have static methods in an interface (with body). You need to call them using the name of the interface, just like static methods of a class.

Can we achieve abstraction without encapsulation?

The object is the abstract form of the real-world and its details are hidden using encapsulation. Thus encapsulation is required for abstraction.

Can we override final method in Java?

You can declare some or all of a class's methods final. You use the final keyword in a method declaration to indicate that the method cannot be overridden by subclasses. The Object class does this—a number of its methods are final .

Which class Cannot be inherited?

An abstract class cannot be inherited by structures. It can contains constructors or destructors. It can implement functions with non-Abstract methods.

Can we create instance of sealed class?

you can create instance of sealed class but not in static class. You need the class name to access the members and methods of static class whereas in case of sealed class you can create the instance of it.