ArrayList - class

boolean contains(Object o)

• Iterate through array—stop at last index (size - 1)

• Check if current index value is equal to object

  • Return true

• Otherwise—return false

int indexOf(Object o)

• Iterate through array—stop at last index (size - 1)

• If current index value equals object

  • Return index

• Otherwise—return -1

E get(int index)

• If the index is inbounds

  • Return value at that index

boolean add(E e)

• Ensure the capacity can add 1 more—size + 1

• Put e at the next open spot—size

• Increment size

E set(int index, E element)

• Make sure index is inbounds

• Hold former

• Set index to new element

• Return former

Object[] toArray()

• Create new array with capacity of size

• iterate through current array—put each element in new array

• Return new array

boolean remove(Object o) — KEY

• Invoke indexOf() to get index of object

  • Return false if -1

• Iterate from that index—to 1 before the last element

  • Each iteration will shift each element to the left

• Delete the duplicate of the final element—size - 1

• Decrement size

E remove(int index) — KEY

• 

  Store the value that we are removing—at index

• Iterate from the index—to 1 before the last element

  • Each iteration will shift each element to the left

• Delete the duplicate of the final element—size - 1

• Decrement size

void add(int index, E element) — KEY

• Make sure the index is bounds

• Ensure the capacity can add 1 more element— index + 1

• Reverse for loop

  • Start at 1 after last element

  • Shift all elements to the right—stopping at 1 before index

• Assign “element” to the duplicate at index

• Increment size

boolean addAll(Collection<E> c)

• Ensure the capacity can hold size + the size of the collection

• Iterator on collection—send over each element to add()

void ensureCapacity(int minCapacity)

• Check if capacity is less than min

  • Create new capacity

  • Double check—new capacity greater than min

  • Create new array with new capacity

  • Iterate through each element—add to new array

  • Overwrite elementData with new array

ArrayListIterator — inner class

• hasNext()

  • Make sure nextIndex is a valid index

• next()

  • Hold element at nextIndex

  • Check if its null

  • Advance nextIndex

  • Return value