Quick Answer: Can An Abstract Class Have A Constructor?

Can abstract class have constructor in 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 abstract class have constructor in CPP?

A class with one (or more) virtual pure functions is abstract, and it can’t be used to create a new object, so it doesn’t have a constructor.

Why does an abstract class have a constructor?

Abstract classes require constructors to enforce a design contract using which objects can be initialized. Constructor can be used to setting up an attribute of the base class. This attribute will be available in subclass by inheritance. Before using this attribute, using the constructor it can be initialized.

Can abstract class be inherited?

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.

Why constructor is not overridden?

Constructor Overriding is never possible in Java. This is because, Constructor looks like a method but name should be as class name and no return value. Overriding means what we have declared in Super class, that exactly we have to declare in Sub class it is called Overriding.

Can abstract class have static methods?

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.

Can a constructor be final?

No, a constructor can’t be made final. A final method cannot be overridden by any subclasses. … But, in inheritance sub class inherits the members of a super class except constructors. In other words, constructors cannot be inherited in Java therefore, there is no need to write final before constructors.

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.

Can abstract class have constructor PHP?

PHP 5 introduces abstract classes and methods. Classes defined as abstract cannot be instantiated, and any class that contains at least one abstract method must also be abstract. … This also applies to constructors as of PHP 5.4. Before 5.4 constructor signatures could differ.

Why we Cannot make constructor final?

A constructor is never inherited to an another class so it doesn’t need to be marked final. Hey, The constructor cannot be final because the constructor cannot be inherited and in constructor values are initialized to the variable so by this variables changes every time and yes it cannot be inherited.

Can abstract class have final methods?

therefore, a final abstract combination is illegal for classes. Hence, a final class cannot contain abstract methods whereas an abstract class can contain a final method.

Can abstract class have body?

Abstract methods are declaration only and it will not have implementation. It will not have a method body. A Java class containing an abstract class must be declared as abstract class. An abstract method can only set a visibility modifier, one of public or protected.

Can constructor be declared as private?

Yes, we can declare a constructor as private. If we declare a constructor as private we are not able to create an object of a class. We can use this private constructor in the Singleton Design Pattern.

Can abstract class have main method?

Yes, you can use the main method in abstract class. The main method is a static method so it is associated with Class, not with object/ instance. … In main method, you can not create an instance of the abstract class but you can instantiate other concrete class.