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] |