LinkedHashSet is a collection in Java that maintains the insertion order of elements. It is part of the Java Collections Framework and extends the HashSet class. It stores unique elements and allows null values, but only one null element. It is similar to HashSet; the main difference is that a LinkedHashSet maintains a linked list holding of the entries of the current object, allowing it to maintain the order of elements. Let's learn how to get the size of a LinkedHashSet in Java. The following are some example scenarios: Scenario 1 Input : set = {1, 2, 3, 4, ... Read More

LinkedHashSet is a part of Java's Collection Framework. It is a type of Set that keeps the order of elements the same as they were added. It uses a combination of a hash table and a linked list to store elements.Our task is to traverse/iterate through the elements of a LinkedHashSet in Java. Let's look at some scenarios to understand the problem better: Scenario 1 Input: {1, 2, 3, 4, 5} Output: 1 2 3 4 5 Explanation: The LinkedHashSet contains the elements 1, 2, 3, 4, and 5. When we iterate through it, we get the elements in the ... Read More

An ArrayList can be created from another collection using the java.util.Arrays.asList() method. A program that demonstrates this is given as follows −Example Live Demoimport java.util.ArrayList; import java.util.Arrays; import java.util.List; public class Demo {    public static void main(String args[]) throws Exception {       String str[] = { "John", "Macy", "Peter", "Susan", "Lucy" };       List aList = new ArrayList(Arrays.asList(str));       System.out.println("The ArrayList elements are: " + aList);    } }OutputThe ArrayList elements are: [John, Macy, Peter, Susan, Lucy]Now let us understand the above program.The string array str[] is defined. Then an ArrayList is created using ... Read More

Elements can be filled in a Java int array in a specified range using the java.util.Arrays.fill() method. This method assigns the required int value in the specified range to the int array in Java.The parameters required for the Arrays.fill() method are the array name, the index of the first element to be filled(inclusive), the index of the last element to be filled(exclusive) and the value that is to be stored in the array elements.A program that demonstrates this is given as follows −Example Live Demoimport java.util.Arrays; public class Demo {    public static void main(String[] argv) throws Exception {     ... Read More

The headset() method returns elements up to a limit defined as a parameter.First, create a NavigableSet and add elements −NavigableSet set = new TreeSet(); set.add(10); set.add(25); set.add(40); set.add(55); set.add(70); set.add(85); set.add(100);Now, use the headset() method −set.headSet(55));The following is an example −Example Live Demoimport java.util.NavigableSet; import java.util.TreeSet; public class Demo {    public static void main(String[] args) {       NavigableSet set = new TreeSet();       set.add(10);       set.add(25);       set.add(40);       set.add(55);       set.add(70);       set.add(85);       set.add(100);       System.out.println("Returned Value = " + ... Read More

Use the lastEntry() method in TreeMap to retrieve the last entry.Create a TreeMap and add some elements −TreeMap m = new TreeMap(); m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");Now, retrieve the last entry −m.lastEntry()The following is an example to retrieve last entry in the TreeMap −Example Live Demoimport java.util.*; public class Demo {    public static void main(String args[]) {       TreeMap m = new TreeMap();       m.put(1, "India");       m.put(2, "US");       m.put(3, "Australia");       m.put(4, "Netherlands");       m.put(5, "Canada");       for(Map.Entry e:m.entrySet()) ... Read More

To display the last entry from NavigableMap in Java, use the lastEntry() method.Let us first create NavigableMap.NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); n.put("C", 868); n.put("D", 988); n.put("E", 686); n.put("F", 888); n.put("G", 999); n.put("H", 444); n.put("I", 555); n.put("J", 666);Get the last entry now.n.lastEntry()The following is an example to get the last entry from NavigableMap.Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put("A", 498); n.put("B", 389); ... 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++) { s.add(a[i]); }After that, use TreeSet class to sort.TreeSet sorted = new TreeSet(s);Get the first element, using the first() method −System.out.println("First element of the sorted set = "+ (Integer)sorted.first());The following is the code to get the first element from a Sorted Set ... 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 java.util.Set; import java.util.HashSet; public class Main { public static void main(String[] args) { List l = new ArrayList(); l.add("Accent"); l.add("Speech"); l.add("Diction"); ... Read More

Getting higher key means to return the least key strictly greater than the given key. This is done using higherKey() method in Java.The following is an example.Example Live Demoimport java.util.*; public class Demo { public static void main(String[] args) { NavigableMap n = new TreeMap(); n.put(5, "Tom"); n.put(9, "John"); n.put(14, "Jamie"); n.put(1, "Tim"); n.put(4, "Jackie"); n.put(15, "Kurt"); n.put(19, "Tiger"); n.put(24, "Jacob"); System.out.println("NavigableMap elements..."+n); System.out.println("Higher Key = "+n.higherKey(15)); } }OutputNavigableMap elements... {1=Tim, 4=Jackie, 5=Tom, 9=John, 14=Jamie, 15=Kurt, 19=Tiger, 24=Jacob} Higher Key = 19