Question

I have an ArrayList<Integer> that is full of years that it pulls from my database i want to know how it is possible to loop through them so i can remove duplicates.
Thanks in Advance,
Dean

Answer 1

Use a Set instead of a List if duplicates shouldn’t exist.

You can either use a Set where you’re currently using your List, or you can use the Set to remove duplicate elements.

Set<Integer> years = new HashSet<Integer>(myOldArrayList);

Or you could transform from one collection to another. I’m not sure what performance implications there are:

ArrayList<Integer> years = // populate from database
years = new ArrayList<Integer>(new HashSet<Integer>(years));