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javaarraysunique

Array of unique elements?

Given an array like the one below, I was wondering if there is an easy way to turn this array into an array with unique values only?

This is given:

   numbers={5,5,4,3,1,4,5,4,5}

Turn it into a result array like this, preserving the original order:

   {5,1,2,3,4}
Solution

  • In Java 8, use IntStream to get unique elements of an array

    int[] noDuplicates = IntStream.of(array).distinct().toArray();

    The simplest way would be to create set from the array.

    Integer[] array = ...
Set<Integer> set = new LinkedHashSet<Integer>(Arrays.asList(array ));

    and then you can retrieve the array using:

    set.toArray()

    use LinkedHashSet if you want to maintain the order or TreeSet if you want to have it sorted.