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Java TreeSet ceiling() method with Example

TreeSet Class ceiling() method: Here, we are going to learn about the ceiling() method of TreeSet Class with its syntax and example.
Submitted by Preeti Jain, on February 20, 2020

TreeSet Class ceiling() method

• ceiling() method is available in java.util package.
• ceiling() method is used to return the lowest element equal to or larger than the given element (ele) when it exists otherwise it returns null.
• ceiling() method is a non-static method, it is accessible with the class object only and if we try to access the method with the class name then we will get an error.
• ceiling() method may throw an exception at the time of returning the least element in this TreeSet.
  • ClassCastException: This exception may throw when the given parameter is incompatible to compare.
  • NullPointerException: This exception may throw when the given parameter is null exists.

Syntax:

    public Element ceiling(Element ele);

Parameter(s):

• Element ele – represents the element (ele) to meet with other elements in this TreeSet.

Return value:

The return type of the method is Element, it returns least element exists in this TreeSet equal to or larger than the given element (ele).

Example:

// Java program to demonstrate the example 
// of Element ceiling(Element ele) method of TreeSet 

import java.util.*;

public class CeilingOfTreeSet {
    public static void main(String[] args) {
        // Instantiates a TreeSet object
        TreeSet < String > tree_set = new TreeSet < String > ();

        // By using add() method is to add
        // the given object of this
        // TreeSet if not exists
        tree_set.add("C");
        tree_set.add("C++");
        tree_set.add("JAVA");
        tree_set.add("PHP");
        tree_set.add("SFDC");

        // Display TreeSet
        System.out.println("TreeSet: " + tree_set);

        // By using ceiling() method is to return
        // the least value element greater than or 
        // equal to the given value element exists
        // in this TreeSet i.e. JAVA
        Object ob = tree_set.ceiling("COBOL");

        // Display ob
        System.out.println("tree_set.ceiling(COBOL): " + ob);
    }
}

Output

TreeSet: [C, C++, JAVA, PHP, SFDC]
tree_set.ceiling(COBOL): JAVA