SortedSet interface in java

SortedSet interface:

SortedSet interface extends Set interface. SortedSet interface maintain ascending order in its elements.
 Note: SortedSet interface declares its own methods in addition of methods declared in Set interface.

 Commonly used methods of SortedSet interface:

1. comparator(): Returns comparator for this sorted set. It returns null if the natural ordering is used for this set.

Syntax: public Comparator comparator().

2. first(): Returns the first element in this sorted set.

Syntax: public Object first().

3. headSet(Object end): Returns a SortedSet containing those elements less than end that are contained in this sorted set.

Syntax: public SortedSet headSet(Object end).

4. last(): Returns the last element in this sorted set.

Syntax: public Object last().

5. subSet(Object start, Object end): Returns a SortedSet containing those elements between start and end -1.

Syntax: public SortedSet subSet(Object start, Object end).

6. tailSet(Object start): Returns a SortedSet that contains those elements greater than or equal to start that are contained in this sorted set.

Syntax: public SortedSet tailSet(Object start).

 A simple example of TreeSet class to explain few methods of SortedSet interface.

TreeSetTest.java

import java.util.Iterator;
import java.util.Set;
import java.util.TreeSet;
 
/**
 * This class is used to show the TreeSet functionality.
 * @author w3schools
 */
public class TreeSetTest {
	public static void main(String args[]){
		//Create TreeSet object.
		Set treeSet = new TreeSet();
 
		//Add objects to the HashSet.
		treeSet.add("Roxy");
		treeSet.add("Sunil");
		treeSet.add("Sandy");
		treeSet.add("Munish");
		treeSet.add("Pardeep");
 
		//Print the TreeSet object.
		System.out.println("TreeSet elements:");
		System.out.println(treeSet);
 
		//Print the TreeSet elements using iterator.
		Iterator iterator=treeSet.iterator();
		System.out.println("TreeSet elements using iterator:");
		while(iterator.hasNext()){  
		   System.out.println(iterator.next());  
		}  
	}
}

Output:

TreeSet elements:
[Munish, Pardeep, Roxy, Sandy, Sunil]
TreeSet elements using iterator:
Munish
Pardeep
Roxy
Sandy
Sunil

Download this example.
 
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