Why do we need inner class?
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.
What are the advantages of inner classes in Java?
The main advantages of a nested (inner) class are:
- It shows a special type of relationship, in other words, it has the ability to access all the data members (data members and methods) of the main class including private.
- They provide easier code because it logically groups classes in only one place.
Why do we need anonymous inner class in Java?
An anonymous inner class can be useful when making an instance of an object with certain “extras” such as overriding methods of a class or interface, without having to actually subclass a class. Tip: Anonymous inner classes are useful in writing implementation classes for listener interfaces in graphics programming.
What is difference between nested and inner class?
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.
What is the advantage of inner class in Java?
The main advantages of a nested (inner) class are: It shows a special type of relationship, in other words, it has the ability to access all the data members (data members and methods) of the main class including private. They provide easier code because it logically groups classes in only one place.
Is it good practice to use inner class in Java?
Any additional encapsulation, such as making the entire inner class private , is desirable; but public inner classes are perfectly acceptable. There are many examples in Java, such as AbstractMap.
What is difference between inner class and subclass?
inner classes are in the same file, whereas subclasses can be in another file, maybe in another package. You cannot get an instance of an inner class without an instance of the class that contains it. inner classes have the methods they want, whereas subclasses have the methods of their parent class.
Can we write class inside a class in Java?
In Java, it is possible to define a class within another class, such classes are known as nested classes. A nested class is also a member of its enclosing class. As a member of its enclosing class, a nested class can be declared private, public, protected, or package private(default).
What are two advantages to using inner classes?
It helps in code optimization.