How to avoid duplicate values from JAVA List / ArrayList

Hiii frnds, this is a nice question in interview forum, so let's see how to remove duplicate objects from List / ArrayList

ArrayListExample.java

package java8s;

import java.util.*;

public class ArrayListExample {

     public static void main(String[] args) {

          ArrayList al=new ArrayList();

          al.add("first");

          al.add("second");

          al.add("third");

          al.add("first");

          al.add("first");

         

          ArrayList al1=new ArrayList(new LinkedHashSet(al));

         

          Iterator it=al1.iterator();

          while(it.hasNext())

          {

              System.out.println(it.next());

          }

     }

}

Output

first

second

third