What is an inner class in Java?

What is an inner class in Java?

Java inner class or nested class is a class that is declared inside the class or interface. We use inner classes to logically group classes and interfaces in one place to be more readable and maintainable. Additionally, it can access all the members of the outer class, including private data members and methods.

Why we use inner classes in Java?

Inner classes are a security mechanism in Java. We know a class cannot be associated with the access modifier private, but if we have the class as a member of other class, then the inner class can be made private. And this is also used to access the private members of a class.

Which is not type of inner class?

Static nested classes are not technically an inner class. They are like a static member of outer class. Anonymous inner classes are declared without any name at all. They are created in two ways.

Can a class be private?

Private classes are allowed, but only as inner or nested classes. If you have a private inner or nested class, then access is restricted to the scope of that outer class. If you have a private class on its own as a top-level class, then you can’t get access to it from anywhere.

Can inner class be public?

Java inner class can be declared private, public, protected, or with default access whereas an outer class can have only public or default access.

How many inner classes can a class have?

Inner class means one class which is a member of another class. There are basically four types of inner classes in java. Nested Inner class can access any private instance variable of outer class.

Why does Java need inner classes?

Why do we need inner classes in Java? Inner classes are a security mechanism in Java. We know a class cannot be associated with the access modifier private, but if we have the class as a member of other class, then the inner class can be made private. And this is also used to access the private members of a class.

How many inner classes a class can have in Java?

There are basically four types of inner classes in java. Nested Inner class can access any private instance variable of outer class. Like any other instance variable, we can have access modifier private, protected, public and default modifier. Like class, interface can also be nested and can have access specifiers.

Are inner classes commonly used in Java?

An inner class in a Java program is nothing but the class that is declared and used in an already functioning class , so as to use all the functions and members which are accessible to the outer class. This is typically used when the coding pattern in the program needs to be more organized while reducing the length of the code.

What is difference between nested and inner class in Java?

In Java programming, nested and inner classes often go hand in hand. A class that is defined within another class is called a nested class. An inner class, on the other hand, is a non-static type, a particular specimen of a nested class. This article attempts to elaborate on these two ideas of designing classes.