How to remove duplicate element from String array and List.

1 ) String Array.
Ex : String nameArray = {“Ram”,”Shyam”,”Mohan”,”Sohan”,”Ram”,”Shyam”,”Mohan”};

2 ) ArraList.
Ex : [“Ram”,”Shyam”,”Mohan”,”Sohan”,”Ram”,”Shyam”,”Mohan”]

As we know the Set collection having the feature to allow the store unique value. Based on that we have follow two step here to removing the duplicate from string array-



Step 1) Convert the String Array into List (ArrayList).
Arrays.asList(nameArray )

The asList() method convert your string array into List.

Step 2) Add this List (ArrayList) into Set (HashSet).
Set set = new HashSet(Arrays.asList(nameArray ));

Program:

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

import java.util.Arrays; import java.util.HashSet; import java.util.LinkedHashSet; import java.util.Set; class RemoveDuplicate { public static void main(String args[]) { String[] nameArray = {"Ram", "Shyam", "Mohan", "Shohan", "Ram", "Shyam","Mohan"}; Set set = new HashSet(Arrays.asList(nameArray )); System.out.println("Output: "+set); } }

The output of this program is :

Output: [Shohan, Mohan, Shyam, Ram]

Note: We are using HashSet so the order is not the same in which we have added the element. If you want to preserve the insertion order choose LinkedHashSet instead of HashSet.

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18

import java.util.Arrays; import java.util.HashSet; import java.util.LinkedHashSet; import java.util.Set; class RemoveDuplicate { public static void main(String args[]) { String[] nameArray = {"Ram", "Shyam", "Mohan", "Shohan", "Ram", "Shyam","Mohan"}; Set set = new LinkedHashSet(Arrays.asList(nameArray )); System.out.println("Output: "+set); } }

The output of this program is :

Output: [Ram, Shyam, Mohan, Shohan]