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.
What are the advantages of using inner and anonymous classes?
The anonymous inner class has advantage over the inner class (as in the question example code) in that it closes over the local variables of the method (although only final locals are usable). Generally an inner class can be easily converted into a method with anonymous inner class, which helps reduce verbosity.
What is the benefit of nested class?
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 the advantage of static inner class?
6 Answers. If the nested class does not access any of the variables of the enclosing class, it can be made static. The advantage of this is that you do not need an enclosing instance of the outer class to use the nested class.
What are disadvantages of using inner classes?
Inner classes have their disadvantages. From a maintenance point of view, inexperienced Java developers may find the inner class difficult to understand. The use of inner classes will also increase the total number of classes in your code.
Why do we use 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.
Can anonymous class have constructor?
An anonymous class cannot have a constructor. … An anonymous class can access any variables visible to the block within which the anonymous class is declared, including local variables. An anonymous class can also access methods of the class that contains it.
Is inner class a good practice?
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 are the advantages and disadvantages of nested classes?
And the benefit of it is you can have less number of objects created at runtime which wouldn’t be the case with other types of nested classes. Disadvantage The only disadvantage I can think of is a static nested class has access to both the protected and private members of the outer class.
What are the types of inner classes?
There are four types of inner classes: member, static member, local, and anonymous.
- A member class is defined at the top level of the class. …
- A static member class is defined like a member class, but with the keyword static. …
- A local inner class is defined within a method, and the usual scope rules apply to it.
Why are inner classes bad?
Non-static inner classes can hide a performance problem. They do have access to member fields on the enclosing class, but not directly, but via getters which are created automatically. This will be slower then just copying the members of the enclosing class to the inner class.
Can we declare local inner classes as static?
An inner class that is declared inside a method of the outer class is called method local inner class in Java. … Therefore, the declaration of method local inner class cannot use any access modifiers such as public, protected, private, and non-access modifiers such as static.
What is the advantage of static class in Java?
Benefits of Static class in java
We can define the related or helper classes inside the class by making it static. It can access the private member of the enclosing class through the object reference. It provides a nice namespace for the nested class.