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javalistcollectionsarraylistduplicates

How do I remove repeated elements from ArrayList?

I have an ArrayList<String>, and I want to remove repeated strings from it. How can I do this?

Solution

  • If you don't want duplicates in a Collection, you should consider why you're using a Collection that allows duplicates. The easiest way to remove repeated elements is to add the contents to a Set (which will not allow duplicates) and then add the Set back to the ArrayList:

    Set<String> set = new HashSet<>(yourList);
yourList.clear();
yourList.addAll(set);

    Of course, this destroys the ordering of the elements in the ArrayList.