TreeSet ceiling() method in Java with Examples Last Updated : 04 Apr, 2019 Comments Improve Suggest changes Like Article Like Report The ceiling() method of java.util.TreeSet<E> class is used to return the least element in this set greater than or equal to the given element, or null if there is no such element. Syntax: public E ceiling(E e) Parameters: This method takes the value e as a parameter which is to be matched. Return Value: This method returns the least element greater than or equal to e, or null if there is no such element. Exception: This method throws NullPointerException if the specified element is null and this set uses natural ordering, or its comparator does not permit null elements. Below are the examples to illustrate the ceiling() method Example 1: Java // Java program to demonstrate // ceiling() method import java.util.*; public class GFG1 { public static void main(String[] argv) throws Exception { try { // create tree set object TreeSet<Integer> treeadd = new TreeSet<Integer>(); // populate the TreeSet treeadd.add(10); treeadd.add(20); treeadd.add(30); treeadd.add(40); // Print the TreeSet System.out.println("TreeSet: " + treeadd); // getting ceiling value for 25 // using ceiling() method int value = treeadd.ceiling(25); // printing the ceiling value System.out.println("Ceiling value for 25: " + value); } catch (NullPointerException e) { System.out.println("Exception thrown : " + e); } } } Output: TreeSet: [10, 20, 30, 40] Ceiling value for 25: 30 Example 2: To demonstrate NullPointerException. Java // Java program to demonstrate // ceiling() method for NullPointerException import java.util.*; public class GFG1 { public static void main(String[] argv) throws Exception { try { // create tree set object TreeSet<Integer> treeadd = new TreeSet<Integer>(); // populate the TreeSet treeadd.add(10); treeadd.add(20); treeadd.add(30); treeadd.add(40); // Print the TreeSet System.out.println("TreeSet: " + treeadd); // getting ceiling value for null // using ceiling() method System.out.println("Trying to compare" + " with null value "); int value = treeadd.ceiling(null); // printing the ceiling value System.out.println("Ceiling value for null: " + value); } catch (NullPointerException e) { System.out.println("Exception: " + e); } } } Output: TreeSet: [10, 20, 30, 40] Trying to compare with null value Exception: java.lang.NullPointerException Comment More infoAdvertise with us Next Article TreeSet clear() Method in Java R rohitprasad3 Follow Improve Article Tags : Misc Java Java-Collections Java - util package Java-Functions java-treeset +2 More Practice Tags : JavaJava-CollectionsMisc Similar Reads TreeSet in Java TreeSet is one of the most important implementations of the SortedSet interface in Java that uses a Tree(red - black tree) for storage. 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