Why creating an object of the sub class invokes also the constructor of the super class?

Why creating an object of the sub class invokes also the constructor of the super class? When inheriting from another class, super() has to be called first in the constructor. If not, the compiler will insert that call. This is why super constructor is also invoked when a Sub object is created.

Is a subclass object also a superclass object?

A superclass object is a subclass object. The class following the extends keyword in a class declaration is the direct superclass of the class being declared. d. Java uses interfaces to provide the benefits of multiple inheritance.

Is super class instantiated when subclass is instantiated?

When a subclass is instantiated, instantiate all the superclasses are instantiated at the same time. Here, the initialization of superclass attributes is ensured by the call of the superclass constructors, as described in Inheritance and Constructors.

What happens when a sub class object is assigned to a super class object reference?

Assigning subclass object to a superclass variable Therefore, if you assign an object of the subclass to the reference variable of the superclass then the subclass object is converted into the type of superclass and this process is termed as widening (in terms of references).

Why does a child class constructor need to invoke the super () method?

Because it will ensure that when a constructor is invoked, it can rely on all the fields in its superclass being initialised. Yes. A superclass must be constructed before a derived class could be constructed too, otherwise some fields that should be available in the derived class could be not initialized.

Can we create object for super class?

Only a subclass object object is created that has super class variables. This situation is different from a normal assumption that a constructor call means an object of the class is created, so we can’t blindly say that whenever a class constructor is executed, object of that class is created or not.

Can we create object of superclass in subclass?

No. It makes zero sense to allow that. The reason is because subclasses generally define additional behavior. If you could assign a superclass object to a subclass reference, you would run into problems at runtime when you try to access class members that don’t actually exist.

Can we create object in subclass?

In inheritance, subclass acquires super class properties. An important point to note is, when subclass object is created, a separate object of super class object will not be created. Only a subclass object object is created that has super class variables.

Can we create object of Super class from a subclass?

If you create object of subclass, that does not mean it create object of super class. Its just a call to constructor of super class, just to ensure that all the required fields are initialized in super class, but this does not create object of super class.

Why are the superclass constructors of a class called?

The superclass constructors are called because otherwise the object would be left in an uninitialized state, possibly unbeknownst to the developer of the subclass.

Can a sub-class have a reference point of a super class?

In the first case, you’re saying that the object reference has static type of the super class. When you create a new sub-class object, you can have that reference point to it because a sub-class IS-A super class instance. That is one of the main reasons you use inheritance.

Why is Super() called when inheriting from another class in Java?

When inheriting from another class, you must call super () in your constructor. If you don’t, the compiler will insert that call for you as you can plainly see. The superclass constructors are called because otherwise the object would be left in an uninitialized state, possibly unbeknownst to the developer of the subclass.