What is the TreeMap.ceilingKey() method in Java?
In this shot, we will learn how to use the TreeMap.ceilingKey() method in Java.
Introduction
The TreeMap.ceilingKey() method is present in the TreeMap interface inside the java.util package.
The TreeMap.ceilingKey() method is used to return the least key greater than or equal to the key passed as an argument.
Syntax
The syntax of the TreeMap.ceilingKey() is shown below:
K ceilingKey(K key)
Parameter
The TreeMap.ceilingKey() method accepts one parameter, which is the key which needs to be matched.
Return
The TreeMap.ceilingKey() method returns either of the two values:
- Key-value: The least key greater than or equal to the key passed as an argument.
- Null: If no such key exists.
Code
Let’s have a look at the code.
import java.util.*;class Main{public static void main(String[] args){TreeMap<Integer, String> s = new TreeMap<Integer,String>();s.put(2,"Welcome");s.put(12,"to");s.put(31,"Educative.io");s.put(18,"Learn");s.put(25,"Coding");s.put(36,"Java");System.out.println("TreeMap mappings are: "+ s);System.out.println("The key obtained after using " +"ceilingEntry(18) method is: " + s.ceilingKey(20));}}
Explanation:
-
In line 1, we imported the required package.
-
In line 2, we made a
Mainclass. -
In line 4, we made a
main()function. -
In line 6, we declared a
TreeMapconsisting of keys of typeIntegerand values of typeString. -
From lines 8 to 13, we inserted values in the map by using the
TreeMap.put()method. -
In line 15, we displayed the mappings present in the
TreeMap. -
In line 17, we used the
TreeMap.ceilingKey()method to get the least key greater than or equal to the key passed as an argument, and we displayed it.
So, this is how to use the TreeMap.ceilingKey() method in Java.
RELATED TAGS
CONTRIBUTOR
Harsh Jain