List with a sublist of Integers

[nimo frey]

I need a data structure, that can hold such datas:

[[0, 92], [12, 85]]

You see, I have a list and in this list I have a list of Integers. But the sublist needs a size of 2 elements.


How can I declare such a datastructure?

Is this the best way?

// declare a list with a sublist that holds integers
private ArrayList<ArrayList<Integer>> data = new ArrayList<ArrayList<Integer>>();
List<Integer> a = new ArrayList<Integer>();
a.add(0);
a.add(92);
t.getData().add(new ArrayList<Integer>(a));
List<Integer> b = new ArrayList<Integer>();
b.add(12);
b.add(85);
t.getData().add(new ArrayList<Integer>(b));

One minor problem is, that I cannot fix the size of the sublist to 2.

[Seetharaman Venkatasamy]

I really dont understand your question. can you please ellaborate?

do you mean you want to maintain key/value pair?

[Martin Vanyavchich]

If there will be no duplicate keys, you could use a Map implementation, Hashtable or something similar

[Matthew Brown]

If you want to fix the size of the sublist, would an array be a better choice? The outer list wouldn't be constrainted to contain only arrays with two elements, but once added the arrays will always be the same size.

private List<int[]> data = new ArrayList<int[]>();  
data.add(new int[]{0, 92});
data.add(new int[]{12, 85});

Alternatively, you could create a new class containing two ints that you add to a list. The best approach is going to depend on what the data structure actually represents.

[nimo frey]

Hello Martin,

thanks. This is what I need.

I tried to use this:

data.add(Arrays.asList(1,2));

But it does not work.

Your solution works and the size is limited to 2:

data.add(new int[]{12, 85});

thanks.