MyArrayList.java

public class MyArrayList<E>extends MyAbstractList<E> {
	public static final int INITIAL_CAPACITY = 16;
	private E[] data = (E[]) new Object[INITIAL_CAPACITY];
	
	public MyArrayList() {
	}
	
	public MyArrayList(E[] objects) {
	for (int i = 0; i < objects.length; i++)
	add(objects[i]);
	}
	@Override 
	public void add(int index, E e) {
	ensureCapacity();
	
	for (int i = size - 1; i >= index; i--)
	data[i + 1] = data[i];
	
	data[index] = e;
	
	size++;
	}
	
	private void ensureCapacity() {
	if (size >= data.length) {
	E[] newData = (E[])(new Object[size * 2 + 1]);
	System.arraycopy(data, 0, newData, 0, size);
	data = newData;
	}
	}
	
	public void clear() {
	data = (E[])new Object[INITIAL_CAPACITY];
	size = 0;
	}
	@Override 
	public boolean contains(E e) {
	for (int i = 0; i < size; i++)
	if (e.equals(data[i])) return true;
	return false;
	}
	@Override 
	public E get(int index) {
	checkIndex(index);
	return data[index];
	}
	private void checkIndex(int index) {
	if (index < 0 || index >= size)
	throw new IndexOutOfBoundsException
	("index " + index + " out of bounds");
	}
	
	@Override 
	public int indexOf(E e) {
	for (int i = 0; i < size; i++)
	if (e.equals(data[i])) return i;
	return -1;
	}
	
	@Override
	public int lastIndexOf(E e) {
	for (int i = size - 1; i >= 0; i--)
	if (e.equals(data[i])) return i;
	return -1;
	}
	
	@Override 
	public E remove(int index) {
	checkIndex(index);
	E e = data[index];
	
	for (int j = index; j < size - 1; j++)
	data[j] = data[j + 1];
	data[size - 1] = null; 

	size--;
	return e;
	}
	@Override 
	public E set(int index, E e) {
	checkIndex(index);
	E old = data[index];
	data[index] = e;
	return old;
	}
	
	@Override
	public String toString() {
	StringBuilder result = new StringBuilder("[");
	for (int i = 0; i < size; i++) {
	result.append(data[i]);
	if (i < size - 1) result.append(", ");
	}
	return result.toString() + "]";
	}
	public void trimToSize() {
		if (size != data.length) {
		E[] newData = (E[])(new Object[size]);
		System.arraycopy(data, 0, newData, 0, size);
		data = newData;
		} // If size == capacity, no need to trim
		}
	
		@Override
		public java.util.Iterator<E> iterator() {
		return new ArrayListIterator();
		}
		private class ArrayListIterator
		implements java.util.Iterator<E> {
		private int current = 0; 
		
		@Override
		public boolean hasNext() {
		return (current < size);
		}
		
		@Override
		public E next() {
		return data[current++];
		}
		
		@Override
		public void remove() {
		MyArrayList.this.remove(current);
		}
		}}