Convert HashSet to TreeSet in java (example)

What is HashSet in java?

  • HashSet class implements the Set interface, backed by a hash table.
  • HashSet contains the unique elements.
    • HashSet does not contains any duplicate keys
    • HashSet can have only 1 null key.
  • HashSet does not maintained the order of elements or keys.
  • HashSet is UnSynchronized and not thread safe.

Program – Convert HashSet<String> to TreeSet<String>

package org.learn.collection.set.hset;
 
import java.util.HashSet;
import java.util.Set;
import java.util.TreeSet;
 
public class DemoHashSetToTreeSet {
 
    public static void main(String[] args) {
        Set<String> setSports = new HashSet<>();
        setSports.add("Tennis");
        setSports.add("Cricket");
        setSports.add("Tennis");
        setSports.add("Basketball");
        setSports.add("Golf");
        setSports.add("Boxer");    
         
        System.out.println("Set: "+ setSports);
         
        Set<String> hashSetToTreeSet = new TreeSet<>(setSports);
        System.out.println("TreeSet:"+hashSetToTreeSet);       
    }
}

Output – convert HashSet to TreeSet in java

Set: [Tennis, Cricket, Golf, Basketball, Boxer]
TreeSet:[Basketball, Boxer, Cricket, Golf, Tennis]