Tutorial 42 Inner Clases

//Tutorial 42 Inner Clases


//---------------------------------------------------------------------------------------------------------------------------------------
//App.java

public class App {

    public static void main(String[] args) {

    Robot robot= new Robot(7);
    robot.start();

    Robot.Battery battery = new Robot.Battery();
    battery.charge();
    }

}
//---------------------------------------------------------------------------------------------------------------------------------------
//Robot.java

public class Robot {

    private int id;
    //Non Static Inner Class
    private class Brain { //inner class
        public void think(){
            System.out.println("Robot " + id + " is thinking. ");
        }
    }
    //Second Type of Inner Class: Static Inner Class

    /* static inner classes do not have access to instance data.
       They are really just like "normal" classes, except that they are grouped
       within an outer class. Use them for grouping classes together.
     */
    public static class Battery {
        public void charge(){
            System.out.println("Battery charging...");
        }
    }

    public Robot(int id) { //rightclick>source>generate constructor using id>delete "super();" because its not needed
        this.id = id;
    }

    public void start(){
        System.out.println("Starting robot " + id);
        // Use Brain. We don't have an instance of brain
        // until we create one. Instances of brain are
        // always associated with instances of Robot (the
        // enclosing class).

        Brain brain = new Brain();
        brain.think();

    // Sometimes it's useful to create local classes
    // within methods. You can use them only within the method.

    final String name = "Robert";

    class Temp {
            public void doSomething() {
                System.out.println("ID is: " + id);
                System.out.println("My name is " + name);
            }
        }
    Temp temp = new Temp();
    temp.doSomething();
    }
}

//---------------------------------------------------------------------------------------------------------------------------------------
/* Run Results:
Robot 7 is thinking.
ID is: 7
My name is Robert
Battery charging...
*/