- What happens if we create object of abstract class?
- Can we create interface object and abstract class?
- Which is better abstract class or interface?
- Can abstract class be empty?
- Can abstract class have constructor C++?
- Can constructor be static?
- What is purpose of abstract class?
- Why you Cannot instantiate an object of an abstract class?
- Can we create constructor in abstract class?
- Can we make object of interface?
- Can we inherit abstract class?
- Can an interface have a constructor?
What happens if we create object of abstract class?
you can’t create a object of abstract class because there is an abstract method which has nothing so you can call that abstract method too.
If we will create an object of the abstract class and calls the method having no body(as the method is pure virtual) it will give an error..
Can we create interface object and abstract class?
You cannot create an object of abstract class or interface since they are incomplete class (interface is not even considered as a class.) … For interface, you must create a class which implement the interface and implement bodies of interface methods.
Which is better abstract class or interface?
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.
Can abstract class be empty?
A empty abstract class can be used to group together classes. This is in order to show some intent and to ensure the single responsibility principle that a class should have just one purpose. The example you give uses an interface, not an empty 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. It is important to have a destructor to delete the memory allocated for the class.
Can constructor be static?
A static constructor does not take access modifiers or have parameters. A class or struct can only have one static constructor. Static constructors cannot be inherited or overloaded. A static constructor cannot be called directly and is only meant to be called by the common language runtime (CLR).
What is purpose of abstract class?
The Purpose of Abstract Classes. The purpose of abstract classes is to function as base classes which can be extended by subclasses to create a full implementation. For instance, imagine that a certain process requires 3 steps: The step before the action.
Why you Cannot instantiate an object of an abstract class?
Because an abstract class is an incomplete class (incomplete in the sense it contains abstract methods without body and output) we cannot create an instance or object; the same way you say for an interface. You CAN instantiate an abstract class. You only need to provide a concrete subclass.
Can we create constructor in abstract class?
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 make object of interface?
No, you cannot instantiate an interface. Generally, it contains abstract methods (except default and static methods introduced in Java8), which are incomplete.
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 an interface have a constructor?
No, you cannot have a constructor within an interface in Java. You can have only public, static, final variables and, public, abstract, methods as of Java7. From Java8 onwards interfaces allow default methods and static methods.