NavigableMap higherKey() Method in Java

The higherKey() method of NavigableMap interface is used to return the least key strictly greater than the given key, or null if there is no such key.

Syntax:

public K higherKey(K key)

Parameters: This method takes the key k as a parameter.



Return Value: This method returns the least key greater than key, or null if there is no such key.

Exception: This method throws the NullPointerException if the specified key is null and this map uses natural ordering, or its comparator does not permit null keys.

Below are the examples to illustrate the higherKey() method:

Example 1:

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java program to demonstrate
// higherKey() method
// for <Integer, String>
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] args) throws Exception
    {
        try {
  
            // Creating object of NavigableMap
            NavigableMap<Integer, String>
                navmap = new TreeMap<Integer, String>();
  
            // Populating the map
            navmap.put(1, "One");
            navmap.put(2, "Two");
            navmap.put(3, "Three");
            navmap.put(4, "Four");
            navmap.put(5, "Five");
  
            // Pritnig the TreeMap
            System.out.println("NavigableMap: " + navmap);
  
            // Getting higher key value for 3
            // using higherKey() method
            int value = navmap.higherKey(3);
  
            // Printing the value
            System.out.println("The higherKey value "
                               + " for 3: " + value);
        }
  
        catch (NullPointerException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

chevron_right


Output:

NavigableMap: {1=One, 2=Two, 3=Three, 4=Four, 5=Five}
The higherKey value  for 3: 4

Example 2: For NullPointerException

filter_none

edit
close

play_arrow

link
brightness_4
code

// Java program to demonstrate
// higherKey() method
// for NullPointerException
  
import java.util.*;
  
public class GFG1 {
    public static void main(String[] args) throws Exception
    {
        try {
  
            // Creating object of TreeMap<Integer, String>
            NavigableMap<Integer, String>
                navmap = new TreeMap<Integer, String>();
  
            // Populating tree map
            navmap.put(1, "One");
            navmap.put(2, "Two");
            navmap.put(3, "Three");
            navmap.put(4, "Four");
            navmap.put(5, "Five");
  
            // Printnig the NavigableMap
            System.out.println("TreeMap: " + navmap);
  
            // Getting higher key value for null
            // Using higherKey() method
            System.out.println("Trying to get higherKey"
                               + " value for null");
  
            int value = navmap.higherKey(null);
  
            // Printing the value
            System.out.println("Value is: " + value);
        }
  
        catch (NullPointerException e) {
            System.out.println("Exception thrown : " + e);
        }
    }
}

chevron_right


Output:

TreeMap: {1=One, 2=Two, 3=Three, 4=Four, 5=Five}
Trying to get higherKey value for null
Exception thrown : java.lang.NullPointerException


My Personal Notes arrow_drop_up

Check out this Author's contributed articles.

If you like GeeksforGeeks and would like to contribute, you can also write an article using contribute.geeksforgeeks.org or mail your article to contribute@geeksforgeeks.org. See your article appearing on the GeeksforGeeks main page and help other Geeks.

Please Improve this article if you find anything incorrect by clicking on the "Improve Article" button below.