Symmetric difference of two Java arrays

Question

I have two arrays

 String[] ID1={\"19\",\"20\",\"12\",\"13\",\"14\"};

 String[] ID2={\"10\",\"11\",\"12\",\"13\",\"15\"};  

How can I get

Answer 1

Seems like you want the union of the two sets (no duplicates, right?) minus the intersection:

Set union = new HashSet(Arrays.asList(ID1));
union.addAll(Arrays.asList(ID2);

Set intersection = new HashSet(Arrays.asList(ID1));
intersection.retainAll(Arrays.asList(ID2);

union.removeAll(intersection);

// result is left in "union" (which is badly named now)

(I changed your String to Integer, which seems to fit the data better, but it would work with String the same way)