Convert an ArrayList to an object array

Question

Is there a command in java for conversion of an ArrayList into a object array. I know how to do this copying each object from the arrayList into the object array, but I was wondering if would it be done automatically.

I want something like this:

ArrayList<TypeA> a;  // Let's imagine "a" was filled with TypeA objects  TypeA[] array = MagicalCommand(a); 

Answer 1

Something like the standard Collection.toArray(T[]) should do what you need (note that ArrayList implements Collection):

TypeA[] array = a.toArray(new TypeA[a.size()]); 

On a side note, you should consider defining a to be of type List<TypeA> rather than ArrayList<TypeA>, this avoid some implementation specific definition that may not really be applicable for your application.

Also, please see this question about the use of a.size() instead of 0 as the size of the array passed to a.toArray(TypeA[])