Java Learning Note – inner class(2)

Reference: Java Tutorial (Oracle)

 

 

 

Meaning

Characters

 

Inner

class

 

 

help the outer class to realize some function

(ex. iterator of Array)

 

1.inner class can be viewed as a member of an instance outer class, hence, it must depend on an instance. (no static allowed)

 

2.inner class method with be covered by the outer class same name method.

(use this.field  to access inner class members, andOuterClass.this.field to access outer class members)

 

3.it can realize a interface, the outer class return such an interface.(???)

 

Static inner class

same as static class member

1.it can only access static outer member

 

2. have no illustration to outer class

 

Local inner class

class in a block

 

1.it can access final variables in the method where it was stated

( because local inner class will die when the method finished)

Anonymous inner class

 

1. used when an instance of class is needed