Fri Jun 20 09:36:43 EDT 2003
For COM1204, all Iterator test code

==> Iterator1TestArr.java <==
/**
 * Tests Iterator1 example for both array and linked list collections.
 *
 * @author R. P. Futrelle
 * @version 20 June 2003 (started 19 June 2003)
 */

class Iterator1TestArr {

    public static void main(String[] args) {
	
	MyArrayCollection myArr = new MyArrayCollection(10);

	for(int i=0; i < 8; i++) {
	    myArr.add("item " + i);
	}

	MyIterator myIt = myArr.iterator();

	System.out.println("Iterating on my array collection:");

	while(myIt.hasNext()) {
	    System.out.println((String)myIt.next());
	}
    } // main()
}

==> MyArrayCollection.java <==
/**
 * A collection built on an array and returning a MyIterator subclass.
 *
 * @author R. P. Futrelle
 * @version 20 June 2003 (started 19 June 2003)
 */

class MyArrayCollection {

    Object[] storesIt;
    int maxIndexFilled;
    int _capacity;

	// Test this class using main(), w/o iterator
	
	public static void main(String[] args){

		MyArrayCollection tester = new MyArrayCollection(3);
		tester.add("string1");
		tester.add("string2");
		tester.add("string3");
		tester.add("string4");
		tester.add("string5");
		
		System.out.println();
		for(int i = 0; i <=  tester.maxIndexFilled; i++)
			System.out.println(tester.storesIt[i]);
			
		tester.clear();
		tester.add("string10");
		tester.add("string11");
		
		System.out.println();
		for(int i = 0; i <=  tester.maxIndexFilled; i++)
				System.out.println(tester.storesIt[i]);
		
		/* results:
		
		string1
		string2
		string3

		string10
		string11
		*/
			
	} // main()
	
    MyArrayCollection(int capacity) {
    	_capacity = capacity;
		storesIt = new Object[_capacity];
		init();
    }
    
	void init() {
		maxIndexFilled = -1;
		} // init()
	
    MyIterator iterator() {
		return new MyArrayIterator(this);
    }	

	boolean add(Object obj) {
		if(maxIndexFilled >= _capacity - 1)
			return false;
		storesIt[++maxIndexFilled] = obj;
		return true;
		}
		
	void clear() {
		init();
		}
				
} // MyArrayCollection

==> MyArrayIterator.java <==
/**
 * Specialized Iterator for MyArrayCollection.
 *
 * @author R. P. Futrelle
 * @version 20 June 2003 (started 19 June 2003)
 */

class MyArrayIterator implements MyIterator {

    int nextIndexToDo;
    MyArrayCollection _collection;

    MyArrayIterator(MyArrayCollection collection) {
	
		_collection = collection;
		nextIndexToDo = 0;
    }

	public boolean hasNext() {
		return nextIndexToDo <= _collection.maxIndexFilled;
		} // hasNext()

	public Object next() {
		// NOT best practice, need exception
		if (nextIndexToDo > _collection.maxIndexFilled) return null; 
		
		return _collection.storesIt[nextIndexToDo++]; // increment after use
		
	} // next()

} // MyArrayIterator

==> MyIterator.java <==
/**
 * Interface for my Iterator type.
 *
 * @author R. P. Futrelle
 * @version 20 June 2003 (started 19 June 2003)
 */

interface MyIterator {

    boolean hasNext();
    Object next();

}