ArrayList: how does the size increase?

Question

I have a basic question on Java ArrayList.

When ArrayList is declared and initialized using the default constructor, memory space for 10 el

Answer 1

Context java 8

I give my answer here in the context of Oracle java 8 implementation, since after reading all the answers, I found that an answer in the context of java 6 has given by gmgmiller, and another answer has been given in the context of java 7. But how java 8 implementes the size increasement has not been given.

In java 8, the size increasement behavior is the same as java 6, see the grow method of ArrayList:

   private void grow(int minCapacity) {
        // overflow-conscious code
        int oldCapacity = elementData.length;
        int newCapacity = oldCapacity + (oldCapacity >> 1);
        if (newCapacity - minCapacity < 0)
            newCapacity = minCapacity;
        if (newCapacity - MAX_ARRAY_SIZE > 0)
            newCapacity = hugeCapacity(minCapacity);
        // minCapacity is usually close to size, so this is a win:
        elementData = Arrays.copyOf(elementData, newCapacity);
    }

the key code is this line:

int newCapacity = oldCapacity + (oldCapacity >> 1);

So clearly, the growth factor is also 1.5, the same as java 6.