Declaring ArrayLists: difference in Functionality?

Question

I'm curious, When declaring ArrayLists, What is the difference in doing this:

List<String> arrayList1= new ArrayList<String>();

and this:

List<String> arrayList2= new ArrayList<>();

i.e. not declaring the <String> twice?

There's no difference, the second one is equal to the first one, but it is only possible after Java 7. — Dmitry Ginzburg, May 29 '14 at 14:29
Second one is just a code-sugar (it is called diamond notation) — Claudio, May 29 '14 at 14:30

score 1 · Answer 1 · answered May 29 '14 at 14:33

1

the only difference is that the first form is compatible with earlier java versions than java 7.

answered May 29 '14 at 14:33

Leo

score -2 · Answer 2 · answered May 29 '14 at 14:35

-2

And you don't need the <> either in latter versions. e.g

List<String> arrayList2= new ArrayList();

answered May 29 '14 at 14:35

RichieHH

This is *not* the same thing. Here, you're assigning a raw type to a generic variable, and so do *not* get the type safety generics provides. – awksp May 29 '14 at 14:39
For more information about raw types, see [this section](http://www.angelikalanger.com/GenericsFAQ/FAQSections/ParameterizedTypes.html#Raw) of the excellent GenericsFAQ. – Edd May 29 '14 at 14:51

2 Answers2