If you have an arrayList of string values and if you want to extract all unique values from it.A seemingly obvious way to do this would be to create a list and before adding the next item to check that an identical item doesn’t already exist in the list.
ArrayList uuniqueList = new ArrayList();
for (Object myObj : myList)
or There is a collection in Java collection framework which we can use to add only unique values no duplicates are allowed in that.
The collection name is HashSet.
HashSet ht=new HashSet();
ht.add(“R1”);// now the first element value is going to be replaced with this one
System.out.println(“Output: “+ht); //Output: [R2, R1]