HashSet usage with int arrays

Question

As I have an ArrayList of int arrays which contains duplicates, I\'d like to use HashSet. Unfortunately, I can\'t manage to use HashSet as I wish:

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Answer 1

Arrays don't override hashCode and equals implemented in Object class, and therefore, two arrays a1 and a2 will be considered as identical to each other by HashSet only if a1==a2, which is false in your case.

If you use ArrayLists instead of arrays, your problem will be solved, since for ArrayLists equality is determined by the equality of the members of the lists (and the order in which they appear).