How would you implement a custom, resizable dynamic array (similar to ArrayList's internal mechanism) from scratch using a raw Java array, including the amortized doubling growth strategy?

A dynamic array wraps a fixed-size backing array along with a separate size counter (tracking logically used elements, distinct from the backing array's full capacity); when an add operation would exceed capacity, allocate a new backing array (conventionally double the current capacity) and copy existing elements over via System.arraycopy() -- this doubling strategy gives amortized O(1) add performance, since the expensive resize-and-copy operation happens increasingly rarely relative to the number of cheap O(1) adds, exactly matching how java.util.ArrayList is implemented internally.

public class SimpleDynamicArray<T> {
    private Object[] data = new Object[10];
    private int size = 0;

    public void add(T element) {
        if (size == data.length) {
            data = Arrays.copyOf(data, data.length * 2);  // double capacity
        }
        data[size++] = element;
    }

    @SuppressWarnings("unchecked")
    public T get(int index) {
        if (index < 0 || index >= size) throw new IndexOutOfBoundsException();
        return (T) data[index];
    }

    public int size() { return size; }
}