CSC 313: Data Structures in Java

Autumn 2002

Inidividual Assignment 4

Object Collections and Iterators

Due Wednesday October 23 before 11:30pm

In this course, we study the SimpleCollection class and the SimpleIterator class. The SimpleCollection class holds a collection of Objects and SimpleIterator provides an iterator for it. In this assignment you will document and expand the functionality of both of these classes.

For the SimpleCollection class, you will add the following functionalities:

• Modify the add method so that the capacity of the array is automatically doubled whenever more capacity is needed.
• Provide a size method that returns how many objects are currently stored in the collection.
• Provide a countOccurrences method that takes an object as an argument and returns a count of how many times that object appears (as defined by the equals method) in the collection.
• Provide a containsAll method that takes a SimpleCollection object as an argument and returns true if every object in the passed collection is present in the collection. Otherwise, the method returns false.

For the SimpleIterator class, you will implement one additional method:

• The remove method, which deletes the object that was most recently retrieved from the next method. The method should throw an IllegalStateException if the next method has not yet been called, or the remove method has already been called after the last call to the next method. Hint: add a boolean instance variable to your class that keeps track of whether the current object has been deleted.

Within the main method of the SimpleIterator class, provide additional test code that demonstrates that all of the methods in your classes work correctly. Make sure you fully document your classes according to the standards of the text and javadoc.

Submission

Before the due date and time, you should submit the following files through the submission Web page:

• Your version of SimpleCollection.java.
• Your version of SimpleIterator.java.