Is not an enclosing class Java?

not an enclosing class error is thrown because of your usage of this keyword. this is a reference to the current object — the object whose method or constructor is being called. With this you can only refer to any member of the current object from within an instance method or a constructor.

What is use of nested class in Java?

As mentioned in the section Nested Classes, nested classes enable you to logically group classes that are only used in one place, increase the use of encapsulation, and create more readable and maintainable code.

What is nested class why it is useful?

Nested classes have access to the private members of the outer class. It is a way of logically grouping classes that are only used in one place. It increases encapsulation. Nested classes can lead to more readable and maintainable code. It is useful for developing object models in your component.

Can we have a class inside another class?

In Java, it is possible to define a class within another class, such classes are known as nested classes. As a member of its enclosing class, a nested class can be declared private, public, protected, or package private(default).

When should you nest classes?

Nested Class can be used whenever you want to create more than once instance of the class or whenever you want to make that type more available. Nested Class increases the encapsulations as well as it will lead to more readable and maintainable code.

Can a class be private in Java?

Yes, we can declare a class as private but these classes can be only inner or nested classes. We can’t a top-level class as private because it would be completely useless as nothing would have access to it.

Are nested classes bad?

They’re not “bad” as such. They can be subject to abuse (inner classes of inner classes, for example). As soon as my inner class spans more than a few lines, I prefer to extract it into its own class. It aids readability, and testing in some instances.

What is setter and getter in Java?

Introduction. Getters and Setters play an important role in retrieving and updating the value of a variable outside the encapsulating class. A setter updates the value of a variable, while a getter reads the value of a variable.

What is wrapper object in Java?

A Wrapper class is a class whose object wraps or contains primitive data types. When we create an object to a wrapper class, it contains a field and in this field, we can store primitive data types. In other words, we can wrap a primitive value into a wrapper class object. Need of Wrapper Classes.