The shortest way to fill the ArrayList

Question

What is the shortest way to fill the ArrayList? Something like:

ArrayList<Integer[]> list = new ArrayList<Integer[]>();
list.add({1,10,1,1});
list.add({2,11,1,1});

Or:

ArrayList<Integer[]> list = ({1,10,1,1},{2,11,1,1});

What do you mean by "shortest"? Least lines of code? For what purpose? — Viruzzo, Jan 03 '12 at 14:31
You can't realistically 'fill' an ArrayList anyway - that's kind of the point of an ArrayList — josh.trow, Jan 03 '12 at 14:33
http://stackoverflow.com/questions/6520382/what-is-the-shortest-way-to-initialize-list-of-strings-in-java check this — Rangi Lin, Jan 03 '12 at 14:35
I wouldn't use `Integer` unless you want `null` values. It can be more efficient and clearer to use `int`. You can have a `List` as `int[]` is an Object. — Peter Lawrey, Jan 03 '12 at 14:59

score 16 · Answer 1 · answered Jan 03 '12 at 14:40

16

How about this shortcut:

List<int[]> list = Arrays.asList( new int[][]{{1,10,1,1}, {2,11,1,1}} );

answered Jan 03 '12 at 14:40

anubhava

score 6 · Answer 2 · answered Jan 03 '12 at 14:35

6

Using guava

Lists.newArrayList(new int[]{1,2,3}, new int[]{2,4,5}, new int[]{5,6,7});

answered Jan 03 '12 at 14:35

Bozho

score 3 · Accepted Answer · answered Jan 03 '12 at 14:35

3

To fix your first attempt:

ArrayList<Integer[]> list = new ArrayList<Integer[]>();
list.add(new Integer[]{1,10,1,1});
list.add(new Integer[]{2,11,1,1});

answered Jan 03 '12 at 14:35

Tudor

score 2 · Answer 4 · answered Jan 03 '12 at 14:36

List<Integer[]> list = new ArrayList<Integer[]>();
list.add(new Integer[] { 1, 10, 1, 1 });
list.add(new Integer[] { 2, 11, 1, 1 });

Or here is a one-liner:

List<Integer[]> list = Arrays.asList(new Integer[] { 1, 10, 1, 1 }, new Integer[] { 2, 11, 1, 1 });

4 Answers4