Generics declaration with wildcard character

Question

Is there any difference in below two?

Code:

List<? extends Object> ls = new ArrayList<String>();
List<?> ls1 = new ArrayList<String>();

There's no difference, because implicitly *every* type extends Object — Bohemian, Oct 19 '13 at 08:55

score 2 · Answer 1 · answered Oct 19 '13 at 08:58

List<? extends Object>

and

List<?>

Both are same. Because collections doen't allow primitives and only Classes ,in java every Class implicitly extends Object.

You can see the difference If you write List<? extends MyOwnParentClass>.

But with Object, you won't get any extra benefit/loss here.

1 Answers1