Getting ceiling key means to return the least key greater than or equal to the given key. For this, use the ceilingKey() method.The following is an example to get ceiling key from NavigableMap.Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { ... Read More

To get enumeration over HashSet, first declare the HashSet and add elements −HashSet hs = new HashSet(); hs.add("P"); hs.add("Q"); hs.add("R");To get enumeration −Enumeration e = Collections.enumeration(hs);The following is an example to get Enumeration over HashSet −Example Live Demoimport java.util.*; public class Demo {    public static void main(String[] args) {   ... Read More

With Java, you can initialize a set without using add() method.For this create a string array −String arr[] = { "A", "B", "C", "D", "E"};Now, use Set and asList() method to initialize the above string array to our Set −Set s = new HashSet(Arrays.asList(arr));The following is an example to initialize ... Read More

Use the contains() method to check if a particular element exists −Set hs = new HashSet(); hs.add(30); hs.add(67); hs.add(88); hs.add(33); hs.add(54); hs.add(90); hs.add(66); hs.add(79);To check for let’s say, element 89, use the contains() method −hs.contains(89));The following is an example to check if a particular element exists in HashSet −Example Live Demoimport ... Read More

The higher() method in NavigableSet returns the least element strictly greater than the given element i.e. 35 here −higher(35);The following is an example to implement the higher method in Java −Example Live Demoimport java.util.NavigableSet; import java.util.TreeSet; public class Demo { public static void main(String[] args) { ... Read More

Use the put() method to add elements to LinkedHashMap collection.First, let us create a LinkedHashMap −LinkedHashMap l = new LinkedHashMap();Now, add elements −l.put("1", "Jack"); l.put("2", "Tom"); l.put("3", "Jimmy"); l.put("4", "Morgan"); l.put("5", "Tim"); l.put("6", "Brad");The following is an example to add elements to LinkedHashMap collection −Example Live Demoimport java.util.LinkedHashMap; public class Demo ... Read More

To convert ArrayList to HashSet, firstly create an ArrayList −List l = new ArrayList();Add elements to the ArrayList −l.add("Accent"); l.add("Speech"); l.add("Diction"); l.add("Tone"); l.add("Pronunciation");Now convert the ArrayList to HashSet −Set s = new HashSet(l);The following is an example to convert an ArrayList to HashSet in Java.Example Live Demoimport java.util.ArrayList; import java.util.List; import ... Read More

To create NavigableMap from TreeMap. The following is the declaration −NavigableMap n = new TreeMap();Now, add some elements to the NavigableMap created above −n.put("A", 888); n.put("B", 999); n.put("C", 444); n.put("D", 555); n.put("E", 666); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);The following is an example to create NavigableMap ... Read More

To create a Sorted Set, firstly create a Set.Set s = new HashSet();Add elements to the above set.int a[] = {77, 23, 4, 66, 99, 112, 45, 56, 39, 89}; Set s = new HashSet(); try { for(int i = 0; i < 5; i++) { ... Read More

To clone the IdentityHashMap in Java, use the clone() method.Create an IdentityHashMap and add elements to it −IdentityHashMap m = new IdentityHashMap(); m.put("1", 100); m.put("2", 200); m.put("3", 300); m.put("4", 150); m.put("5", 110);Now get the size of the IdentityHashMap −m.size()The following is an example to clone IdentityHashMap in Java −Example Live Demoimport ... Read More