Interfaces and Inner Classes - Java - page 696

21. Yes, it is legal to add the method doubleBalance to the inner class Money because

an inner class has access to the instance variables, like balance of the outer class.
To test this out, add the following as a method of the outer class:

public void test()
{
balance.doubleBalance();
}

22. It would be legal. The method makeDeposit is assumed to be the method
makeDeposit of the outer class. The calling object balance is assumed to be the
instance variable of the outer class. These sorts of tricks can lead to confusing
code. So, use them sparingly. This is just an exercise.
23. No, a nonstatic inner class cannot have any static methods.
24. Yes, you can have a nonstatic method in a static inner class.
25. OuterClass.InnerClass.someMethod();
26. Outs outerObject = new Outs();
Outs.Ins innerObject =
outerObject. new Ins();
innerObject.specialMethod();

27. You would get your first error on the following statement and it would be a

complier error:

anObject.setNumber(42);

With the change described in the exercise, anObject is of type Object and
Object has no method named setNumber .

Programming Projects
Many of these Programming Projects can be solved using AW's CodeMate.
To access these please go to: www.aw-bc.com/codemate .

1. Modify the recursive implementation of binary search from Chapter 11 so that

the search method works on any array of type Comparable[] . Test the imple-
mentation with arrays of different types to see if it works.

2. Listed below is the skeleton for a class named InventoryItem . Each inventory

item has a name and a unique ID number:

class InventoryItem
{
private String name;
private int uniqueItemID;
}