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Articles by karthikeya Boyini
Page 67 of 142
Use ListIterator to traverse an ArrayList in the forward direction in Java
A ListIterator can be used to traverse the elements in the forward direction as well as the reverse direction in the List Collection. So the ListIterator is only valid for classes such as LinkedList, ArrayList etc.The method hasNext( ) in ListIterator returns true if there are more elements in the List and false otherwise. The method next( ) returns the next element in the List and advances the cursor position.A program that demonstrates this is given as follows −Exampleimport java.util.ArrayList; import java.util.ListIterator; public class Demo { public static void main(String[] args) { ArrayList aList = new ...
Read MoreGet the count of elements in HashMap in Java
Use the size() method to get the count of elements.Let us first create a HashMap and add elements −HashMap hm = new HashMap(); // Put elements to the map hm.put("Maths", new Integer(98)); hm.put("Science", new Integer(90)); hm.put("English", new Integer(97));Now, get the size −hm.size()The following is an example to get the count of HashMap elements −Exampleimport java.util.*; public class Demo { public static void main(String args[]) { // Create a hash map HashMap hm = new HashMap(); // Put elements to ...
Read MoreGet Size of Java LinkedHashMap
The size() method is used to get the size of LinkedHashMap in Java.Create a LinkedHashMap and add some elements to it −LinkedHashMap l = new LinkedHashMap(); l.put("1", "Jack"); l.put("2", "Tom"); l.put("3", "Jimmy"); l.put("4", "Morgan"); l.put("5", "Tim"); l.put("6", "Brad");Get the size now −l.size()The following is an example to get the size of LinkedHashMap −Exampleimport java.util.LinkedHashMap; public class Demo { public static void main(String[] args) { LinkedHashMap l = new LinkedHashMap(); l.put("1", "Jack"); l.put("2", "Tom"); l.put("3", "Jimmy"); l.put("4", "Morgan"); l.put("5", "Tim"); ...
Read MoreFind the size of a HashMap in Java
Use the size() method to get the size of HashMap. Let us first create a HashMapHashMap hm = new HashMap();Now, add some elements −hm.put("Bag", new Integer(1100)); hm.put("Sunglasses", new Integer(2000)); hm.put("Franes", new Integer(800)); hm.put("Wallet", new Integer(700)); hm.put("Belt", new Integer(600));Since, we added 5 elements above, therefore, the size() method will give 5 as the result −set.size()The following is an example to find the size of HashMap −Exampleimport java.util.*; public class Demo { public static void main(String args[]) { // Create a hash map HashMap hm = new ...
Read MoreCheck if a particular element exists in Java LinkedHashSet
Use the contains() method to check if a specific element exists in LinkedHashSet or not.Let us first create a LinkedHashSet and add some elements −LinkedHashSet l = new LinkedHashSet(); l.add(new String("1")); l.add(new String("2")); l.add(new String("3")); l.add(new String("4")); l.add(new String("5")); l.add(new String("6")); l.add(new String("7"));Now, check whether it contains element “5” or not −l.contains("5")The following is an example to check if a particular element exists in LinkedHashSet −Exampleimport java.util.*; public class Demo { public static void main(String[] args) { LinkedHashSet l = new LinkedHashSet(); l.add(new String("1")); l.add(new String("2")); l.add(new ...
Read MoreConvert elements in a HashSet to an array in Java
First, create a HashSet and elements to it −HashSet hs = new HashSet(); // add elements to the hash set hs.add("B"); hs.add("A"); hs.add("D"); hs.add("E"); hs.add("C"); hs.add("F"); hs.add("K");Let us now convert the above HashSet to an array −Object[] ob = hs.toArray();The following is an example to convert elements in a HashSet to an array −Exampleimport java.util.*; public class Demo { public static void main(String args[]) { // create a hash set HashSet hs = new HashSet(); // add elements to ...
Read MoreConvert a Set into a List in Java
First, create a Set and add elements −Set s = new HashSet(); s.add("P"); s.add(new Date()); s.add(new Long(898999)); s.add("Q"); s.add("R"); s.add(new Integer(1));Convert the above Set to a List −List l = new ArrayList(s);The following is an example to convert a set into a list in Java −Exampleimport java.util.ArrayList; import java.util.Date; import java.util.List; import java.util.Set; import java.util.HashSet; public class Demo { public static void main(String[] args) { Set s = new HashSet(); s.add("P");; s.add(new Date()); s.add(new Long(898999)); s.add("Q"); s.add("R"); s.add(new ...
Read MoreFind maximum element of HashSet in Java
To get the maximum element of HashSet, use the Collections.max() method.Declare the HashSet −Set hs = new HashSet();Now let us add the elements −hs.add(29); hs.add(879); hs.add(88); hs.add(788); hs.add(456);Let us now get the maximum element −Object obj = Collections.max(hs);The following is an example to find maximum element of HashSet −Exampleimport java.util.*; public class Demo { public static void main(String args[]) { // create hash set Set hs = new HashSet(); hs.add(29); hs.add(879); ...
Read MoreFetch key-valuepair from Java LinkedHashSet
To fetch LinkedHashSet key-value pair in Java, use the entrySet() method.Let us first create LinkedHashSet and add some elements −LinkedHashMap l = new LinkedHashMap(); l.put("1", "Jack"); l.put("2", "Tom"); l.put("3", "Jimmy"); l.put("4", "Morgan"); l.put("5", "Tim"); l.put("6", "Brad");Now, fetch a key-value pair −l.entrySet()The following is an example to fetch key-value pair from LinkedHashSet −Exampleimport java.util.*; public class Demo { public static void main(String[] args) { LinkedHashMap l = new LinkedHashMap(); l.put("1", "Jack"); l.put("2", "Tom"); l.put("3", "Jimmy"); l.put("4", "Morgan"); l.put("5", "Tim"); ...
Read MoreCreate a TreeMap in Java and add key-value pairs
A TreeMap cannot contain duplicate keys. TreeMap cannot contain the null key. However, It can have null values.Let us first see how to create a TreeMap −TreeMap m = new TreeMap();Add some elements in the form of key-value pairs −m.put(1, "India"); m.put(2, "US"); m.put(3, "Australia"); m.put(4, "Netherlands"); m.put(5, "Canada");The following is an example to create a TreeMap and add key-value pairs −Exampleimport 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"); ...
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