Programming Articles - Page 2513 of 3366

When write a Java program/class first of all you need to compile it using the javac command as −javac [name of the class].javaIf your program gets compiled without errors, a .class file (byte code) is created with the specified name. Then you need to execute it using the java command (JVM) as −java [class name]ExampleSuppose we Have created a simple class Calculator which adds two or, three numbers in the file with name Calculator.java in the path D:\sample as −public class Calculator {    int addition(int a , int b){       int result = a+b;       ... Read More

An interface in Java is similar to class but, it contains only abstract methods and fields which are final and static.Since Java8 static methods and default methods are introduced in interfaces.Default Methods - Unlike other abstract methods these are the methods can have a default implementation. If you have default method in an interface, it is not mandatory to override (provide body) it in the classes that are already implementing this interface.In short, you can access the default methods of an interface using the objects of the implementing classes.Exampleinterface MyInterface{    public static int num = 100;    public default void ... Read More

Inheritance is a relation between two classes where one class inherits the properties of the other class. This relation can be defined using the extends keyword as −public class A extends B{ }The class which inherits the properties is known as sub class or, child class and the class whose properties are inherited is super class or, parent class.In inheritance a copy of super class members are created in the sub class object. Therefore, using the sub class object you can access the members of the both classes.Exampleclass Super{    int a =100;    int b = 200;    public void ... Read More

The process of wrapping up the data and, the code acting on the data together is known as encapsulation. This is a protective mechanism where we hide the data of one class from (an object of) another.Since, variables hold the data of a class to encapsulate a class you need to declare the required variables (that you want to hide) private and provide public methods to access (read/write) them.By doing so, you can access the variables only in the current class, they will be hidden from other classes, and can be accessed only through the provided methods. Therefore, it is ... Read More

The default methods are introduced in an interface since Java8. Unlike other abstract methods these are the methods can have a default implementation. If you have default method in an interface, it is not mandatory to override (provide body) it in the classes that are already implementing this interface.In short, you can access the default methods of an interface using the objects of the implementing classes.Exampleinterface MyInterface{    public static int num = 100;    public default void display() {       System.out.println("display method of MyInterface");    } } public class InterfaceExample implements MyInterface{    public static void main(String ... Read More

Inheritance is a relation between two classes where one class inherits the properties of the other class. This relation can be defined using the extends keyword as −public class A extends B{ }The class which inherits the properties is known as sub class or, child class and the class whose properties are inherited is super class or, parent class.In inheritance a copy of super class members is created in the sub class object. Therefore, using the sub class object you can access the members of the both classes.Multiple inheritanceThere are various types of inheritance available namely single, multilevel, hierarchical, multiple ... Read More

Yes, an Enum implements an Interface in Java. It can be useful when we need to implement business logic that is tightly coupled with a specific property of a given object or class. Before implementing the interface with an enum, let's discuss enums and interfaces in Java with a code snippet for better understanding. Enum in Java In Java, an Enum (i.e., an enumeration) is a special data type added in Java version 1.5. Enums are constants by default; the names of an enum type's fields are in uppercase letters. In the Java programming language, you can define an Enum ... Read More

A JLabel is a subclass of JComponent class and an object of JLabel provides text instructions or information on a GUI. A JLabel can display a single line of read-only text, an image or both text and an image. A JLabel can explicitly generate a PropertyChangeListener interface. We can also implement a moving text in a JLabel by using a Timer class, it can set a timer with speed(in milliseconds) and this as an argument.Exampleimport java.awt.*; import java.awt.event.*; import java.util.*; import javax.swing.*; import javax.swing.Timer; public class MovingTextLabel extends JFrame implements ActionListener {    private JLabel label;    public MovingTextLabel() {       setTitle("MovingTextLabel");       label= new JLabel(" ... Read More

Here we will see one problem. We have one binary array. It has n elements. Each element will be either 0 or 1. Initially, all elements are 0. Now we will provide M commands. Each command will contain start and end indices. So command(a, b) is indicating that the command will be applied from element at position a to element at position b. The command will toggle the values. So it will toggle from ath index to bth index. This problem is simple. check the algorithm to get the concept.AlgorithmtoggleCommand(arr, a, b)Begin    for each element e from index a ... Read More

Here we will see the area of the biggest square that can be inscribed in an equilateral triangle. The side of the triangle is ‘a’ and the side of the square is x.The side of the triangle ‘a’ is −So x is −Example#include #include using namespace std; float areaSquare(float a) { //a is side of triangle    if (a < 0 ) //if a is negative, then this is invalid       return -1;    float area = a / (1 + 2/sqrt(3));    return area; } int main() {    float a = 7;    cout