Storing number pairs in java

Question

How do I store a set of paired numbers in java? Do I use lists or arrays or maybe something else?

eg. [ (1,1) , (2,1) , (3,5)]

Answer 1

If you're needing to avoid duplicates then a HashSet would be a good choice but it not then an ArrayList would work.

Class IntPair(){
  int i;
  int j;
}
HashSet set = new HashSet();

or

ArrayList list = new ArrayList();