Found 9326 Articles for Object Oriented Programming

The element() method in Java Queues is used to return the element at the front of the container and does not remove it.The following is an example. Firstly, create a Queue and add some elements −Queue q = new LinkedList(); q.offer("abc"); q.offer("def"); q.offer("ghi"); q.offer("jkl"); q.offer("mno"); q.offer("pqr"); q.offer("stu"); q.offer("vwx");Now use the element() method as shown below −System.out.println("Queue head = " + q.element());The following is the complete example −Example Live Demoimport java.util.LinkedList; import java.util.Queue; public class Demo {    public static void main(String[] args) {       Queue q = new LinkedList();       q.offer("abc");       q.offer("def");     ... Read More

An element in an Java LinkedList can be replaced using the java.util.ArrayList.set() method. This method has two parameters i.e the index at which the LinkedList element is to be replaced and the element that it should be replaced with. ArrayList.set() method returns the element that was at the position specified at the index previously.A program that demonstrates this is given as follows −Example Live Demoimport java.util.LinkedList; public class Demo {    public static void main(String[] args) {       LinkedList l = new LinkedList();       l.add("Pear");       l.add("Apple");       l.add("Mango");       l.add("Guava"); ... Read More

A LinkedList can be converted into an ArrayList by creating an ArrayList such that the parameterized constructor of the ArrayList initialises it with the elements of the LinkedList.A program that demonstrates this is given as follows −Example Live Demoimport java.util.ArrayList; import java.util.LinkedList; import java.util.List; public class Demo {    public static void main(String[] args) {       LinkedList l = new LinkedList();       l.add("Orange");       l.add("Apple");       l.add("Peach");       l.add("Guava");       l.add("Pear");       List aList = new ArrayList(l);       System.out.println("The ArrayList elements are: ");     ... Read More

To create a queue using LinkedList class, try the following −Queue q = new LinkedList(); q.offer("abc"); q.offer("def"); q.offer("ghi"); q.offer("jkl"); q.offer("mno"); q.offer("pqr"); q.offer("stu"); q.offer("vwx");After that to print the elements, you need to use check a condition for Queue as shown below −Object ob; while ((ob = q.poll()) != null) {    System.out.println(ob); }The following is an example −Example Live Demoimport java.util.LinkedList; import java.util.Queue; public class Demo {    public static void main(String[] args) {       Queue q = new LinkedList();       q.offer("abc");       q.offer("def");       q.offer("ghi");       q.offer("jkl");       q.offer("mno"); ... Read More

The current method name that contains the execution point that is represented by the current stack trace element is provided by the java.lang.StackTraceElement.getMethodName() method.A program that demonstrates this is given as follows −Example Live Demopublic class Demo {    public static void main(String args[]) {       System.out.println       ("The method name is: " + new Exception().getStackTrace()[0].getMethodName());    } }OutputThe method name is: mainNow let us understand the above program.The method getMethodName() is used to obtain the current method name that contains the execution point that is represented by the current stack trace element. This is printed using ... Read More

The methods of an object can be called using the java.lang.Class.getDeclaredMethods() method. This method returns an array that contains all the Method objects with public, private, protected and default access. However, the inherited methods are not included.Also, the getDeclaredMethods() method returns a zero length array if the class or interface has no methods or if a primitive type, array class or void is represented in the Class object.A program that demonstrates this is given as follows −Example Live Demoimport java.lang.reflect.Method; class ClassA {    private String name = "John";    public String returnName() {       return name;    } ... Read More

Elements can be filled in an int array using the java.util.Arrays.fill() method. This method assigns the required int value to the int array in Java. The two parameters required are the array name 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 {       int[] intArray = new int[5];       int intValue = 9;       Arrays.fill(intArray, intValue);       System.out.println("The int array content is: " + Arrays.toString(intArray)); ... Read More

In order to generate Random double type numbers in Java, we use the nextDouble() method of the java.util.Random class. This returns the next random double value between 0.0 (inclusive) and 1.0 (exclusive) from the random generator sequence.Declaration - The java.util.Random.nextDouble() method is declared as follows −public float nextDouble()Let us see a program to generate random double type numbers in Java −Example Live Demoimport java.util.Random; public class Example {    public static void main(String[] args) {       Random rd = new Random(); // creating Random object       System.out.println(rd.nextDouble()); // displaying a random double value between 0.0 & 1.0   ... Read More

The methods of the java.lang.Math class can be listed using the java.lang.Class.getDeclaredMethods() method. This method returns an array that contains all the Method objects with public, private, protected and default access. However, the inherited methods are not included. Also, the getDeclaredMethods() method returns a zero length array if the class or interface has no methods or if a primitive type, array class or void is represented in the Class object.A program that demonstrates this is given as follows −Example Live Demoimport java.lang.reflect.Method; public class Demo {    public static void main(final String[] args) {       final Method[] methods = Math.class.getDeclaredMethods(); ... Read More

The methods of a class can be listed using the java.lang.Class.getDeclaredMethods() method. This method returns an array that contains all the Method objects with public, private, protected and default access. However, the inherited methods are not included.Also, the getDeclaredMethods() method returns a zero length array if the class or interface has no methods or if a primitive type, array class or void is represented in the Class object.A program that demonstrates this is given as follows −Example Live Demoimport java.lang.reflect.*; public class Demo {    public static void main(String[] args) {       Class c = Thread.class;       ... Read More