CS-151 Labs > Lab 3. My ArrayList

Part 3. Completing MyArrayList

Now spend some time finishing up your implementation of MyArrayList class. Don’t forget to write (and run!) your tests as you go along.

Public Methods

Add the implementation of the following methods to your MyArrayList class or its JUnit test class as appropriate.

E set(int index, E element)

Change the value at the specified index to element. Return the previous value. Throw an IndexOutOfBoundsException if the index is not within the allowed range. Note that this range is smaller than the range allowed for add().

void testSet()

Store the numbers 0 through 20 in the MyArrayList using add(), then use get() and set() to reverse the order of the elements. Iterate through the list and confirm that element i is equal to 20 - i. Add additional code to test the IndexOutofBoundsException.

E remove(int index)

Remove the item at the specified index, shifting all subsequent elements to the left. Return the item that was removed. Throw an IndexOutOfBoundsException if the index is not within the allowed range. Note that this range is smaller than the range allowed for add().

void testRemove()

Insert the numbers 0 through 20, then remove every even-indexed entry, starting at 0 (so, entries 0, 2, 4,…) and add them into a second MyArrayList. Check that your second MyArrayList contains entries 0, 2, 4, …, 20 (in order) and your original MyArrayList contains 1, 3, 5, …, 19) (in order).

boolean isEmpty()

Return true if there are no items stored, false otherwise.

void testIsEmpty()

Test isEmpty() returns true if your array list has no items, and false otherwise. Try testing before you add an element, after, and then after you remove the element.

void clear()

Empty out the list. Be sure to allow garbage collection to take place by setting array entries to null.

void testClear()

Insert multiple elements, then clear. Make sure your size is 0 and you cannot get any elements.