Nested and Inner Classes
Scroll down to class Car
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// Nested class demo - shows one use of each type of nested or inner class.
// Although these classes don't do anything, it is useful to compile this
// file and observe the compiler generated names of the nested classes.
// Remember each class must end up in its own ".class" file, so what do
// you think the names of the annonymous classes will be?
//
// Written 4/2002 by Wayne Pollock, Tampa Florida USA.
class Base // normal class extended later
{
void method1() {}
void method2() {}
}
class Outer // normal class
{
static class InnerStatic {} // nested class
class Inner {} // inner (non-static) class
void f()
{
class Local_Inner {} // local inner class
}
void g()
{
Base bref = new Base() // anonymous class
{ void method1() // that extends "Base"
{} // and overrides method1
};
}
void h ( Base b ) {}
void j ()
{
h( new Base() // common use of annonymous inner class
{ // defined within a method call.
void method2()
{}
}
);
}
}
InnerClassDemo.java
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// Demo showing the special trust relationship of inner classes.
// It also shows the correct way to refer to enclosing class properties
// ("vehicleID") from inner class methods (this syntax is only needed
// if the name is shadowed), and how to construct inner class objects
// (which must be associated with an enclosing class object.)
//
// Written 4/2002 by Wayne Pollock, Tampa Florida USA.
class Car
{
private String vehicleID;
Car ( String vehicleID )
{
this.vehicleID = vehicleID;
}
class Motor
{
private String vehicleID = "123XYZ";
void start ()
{
System.out.println( Car.this.vehicleID + " is running." );
}
}
}
public class InnerClassDemo
{
public static void main ( String [] args )
{
Car ford = new Car( "Wayne's car" );
Car.Motor motor = ford.new Motor();
motor.start();
}
}
