Implementation of toArray(Object[] a)

Question

I'm having trouble grasping one small aspect of the method, specifically:
"Otherwise, a new array is allocated with the runtime type of the specified array and the size of this collection."
As I understand it, if a user passes in an array of String objects and the array is not long enough, I need to allocate a new array of String objects, and not just simply an array of Objects. How exactly would I go about instantiating an array of objects of a specific type that is determined at runtime?

Answer 1

You can look in the src.zip to see how this is done for ArrayList:
public Object[] toArray(Object a[]) {
    if (a.length < size)
        a = (Object[])java.lang.reflect.Array.newInstance(
                                a.getClass().getComponentType(), size);
    System.arraycopy(elementData, 0, a, 0, size);
    if (a.length > size)
         a[size] = null;
    return a;
}