how to remove arraylist duplicate values

Question

I am performing some maintenance tasks on an old system. I have an arraylist that contains following values:

a,b,12
c,d,3
b,a,12
d,e,3
a,b,12

Answer 1

In ArrayList we don't have a chance to remove duplicate elements directly. We can achieve it with sets, because sets don't allow duplicates, so, better to use HashSet or LinkedHashSet classes. See reference.