Hi
From looking at the Java Collections API i see that arrays are not regarded as collections. If not what are arrays regarded as?
+10
A:
Arrays are "special" in Java - they don't implement any interfaces, which means they can't implement the collection interfaces. They're collections in "natural language" terms, and you can use the enhanced for loop over them - but if you want to use an array within the collection API, you'll need something like Arrays.asList which wraps an array with the List<T> interface. (The result is only a view on the array - changes to the array are visible through the list, and vice versa.)
(This is in contrast to .NET, where T[] implements IList<T> etc.)
Jon Skeet
2010-01-18 20:48:00
Thanks Jon, thats a nice helpful answer. Its something i never really thought about before, but im preparing a presentation on some collection topics. I want to be prepared if and when i get asked about arrays. Thanks Jon
2010-01-18 20:51:47
Note that you can change elements through the List, but you cannot add new elements to it, because the backing array cannot grow. You'll get a runtime error if you try.
FredOverflow
2010-01-18 21:00:37