Author: alegru

In Java, an interface is a collection of abstract methods that define a contract or a set of behaviors that a class can implement. Interfaces provide a way to achieve abstraction and polymorphism, enabling objects of different classes to be treated interchangeably based on their common behavior. In this tutorial, we will explore the various…

class Vehicle { // … } class Car extends Vehicle { // … } class Test { public static void main(String[] args){ Car car = new Car(); System.out.println(car instanceof Car); System.out.println(car instanceof Vehicle); } } Output: true true   The above example shows that an object of subclass type is also a superclass type. The instanceof operator works…

Java is an object-oriented programming language that allows developers to create reusable and modular code through the use of classes, objects, and interfaces. One of the key features of Java is the concept of binding, which refers to the association of a method call to the corresponding method body. There are two types of binding…

Java is a popular programming language that is used for a wide variety of applications, ranging from web development to mobile app development to machine learning. One of the features of Java that is particularly important for programmers to understand is the “final” keyword. The “final” keyword in Java is used to indicate that a…

In Java, a static initializer block is a block of code that is executed when a class is loaded into memory. It is typically used to perform some initialization tasks that need to be done before the class can be used, such as initializing static variables, registering JDBC drivers, or building complex data structures. In…

public static void main(String[] args) { { System.out.println(“Summer”); } } { System.out.println(“Winter”); } 1 public class Car { 2 private String model = “Ford”; 3 4 { 5 System.out.println(“Instance Initializer block…”); 6 } 7 8 public Car () { 9 model = “Opel”; 10 System.out.println(“Constructor…”); 11 } 12 13 public static void main(String[] args) {…

class Vehicle { void startEngine() { System.out.println(“Starting the engine…”); } void stopEngine() { System.out.println(“Stopping the engine…”); } } class Car extends Vehicle { void move() { System.out.println(“The car is moving…”); } void invoke() { super.startEngine(); move(); super.stopEngine(); } } class TestSuper2 { public static void main(String args[]){ Car car = new Car(); car.invoke(); } }…

In Java programming, the “this” keyword is used to refer to the current object. It is a reference to the object on which the method or constructor was invoked, and it is typically used to distinguish between class fields and local variables that have the same name. Understanding how to use “this” keyword is important…

In Java programming, the “static” keyword is used to define a class-level entity that can be accessed without the need to create an instance of the class. It is a powerful keyword that can be used to define static variables, methods, blocks, and classes. Understanding the concept of “static” is important for any Java programmer…