type casting

[Renu Radhika]

can an Arraylist be typecast to a vector?

[Ulf Dittmer]

No. But they both extend AbstractList, so you can typecast to that.

[Renu Radhika]

Thanks a lot

[Jeff Albertson]

Originally posted by Ulf Dittmer:
No. But they both extend AbstractList, so you can typecast to that.

True, but note that AbstractList's public methods are precisely
the same as List's, so I would more likely write:

List x = new ArrayList(); 
//versus
AbstractList x = new ArrayList();

On the other hand, I think the OP wanted to *cast* ("convert*) an existing ArrayList
to a Vector: you can't do that, but you can create a new Vector that
holds copies of the references found in the ArrayList:

Vector v = new Vector(arrayList);

Note that v != arrayList, although v.equals(arrayList).

Of course, in the best of all possible worlds, just being of type List should suffice!

[Stuart Ash]

I would mention two principles here that are useful:

1. Vector is old and kind of discouraged. Avoid its use unless there is legacy code which you must add your code to.

2. Use Collections 2 and always strive to use references of the base-interface type. E.g.,

List list = // new ArrayList();
public List getItems(){...}

This way, the implementation can be changed when needed.

[Stefan Wagner]

A lot of classes in javax.swing expect a Vector in the constructor (or an array) but not an arraylist.
That's often a reason for using Vector.