Inner class
- 2. Group related classes and thus reduce namespace clutter defined at a scope smaller than a package An inner class can be defined inside another class, inside a method, and even as part of an expression There are four types of inner classes • static inner classes (also called nested classes) • member inner classes • local inner classes • anonymous inner classes
- 3. The simplest form of inner class Can’t have the same name as the enclosing class Compiled into a completely separate .class file from the outer class Can access only static members and methods of the enclosing class, including private static members Create an instance of a static inner class out of enclosing class: • new outerclass.innerclass()
- 4. Defined in an enclosing class without using the static modifier Like instance variables Can access all members of the enclosing class Create an instance within the enclosing class this.new Innerclass(); Create an instance out of the enclosing class (new Outerclass()).new Innerclass(); Access members of the enclosing class within inner classes Outerclass.this.member
- 5. Defined within the scope of a method, even smaller blocks within methods The least used form of inner class Like local variables, can’t be declared public, protected, private and static Can only access final local variables
- 6. Local inner classes which don’t have class names No key word class No key word extends and implements No constructors Implicitly extend a superclass or implement an interface