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) {…
Read More Java Instance Initializer Blockclass 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(); } }…
Read More Keyword super in Javaclass Colour { public void printColour() { System.out.println(“Colour…”); } } class Blue extends Colour { } class Test { public static void main(String[] args) { Colour colour = new Blue(); colour.printColour(); } } Output: Colour… The superclass method is called because it is not overridden in the subclass. This is okay if we don’t…
Read More Method Overriding in Javapublic ClassA { int data; public void setData(int newData) { this.data = newData; } } public ClassB { int data; public void setData(int data) { this.data = data; } } public ClassC { int data; public ClassC(int data) { // constructor this.data = data; } } public class ClassD { private int day; private int…
Read More Keyword this in Javaclass Car { public static String MODEL = “Ford”; } public class ConstructorExample { public static void main(String[] args) { System.out.println(Car.MODEL); } } Output: Ford Static methods class Car { public static String MODEL = “Ford”; public static void printModel() { System.out.println(“Model is: ” + MODEL); } } Output: Model is: Ford Read more…
Read More Keyword static in JavanameOfTheClass() {} class Car { public Car() { // constructor System.out.println(“The car is mooving!”); } public static void main(String args[]) { Car car = new Car(); // with this, we are actually calling a constructor } } Output: The car is moving! Note: The compiler automatically creates a default constructor if there is no constructor…
Read More Constructor in Javapublic int sum(int a, int b, int c) { // body of the method } sum(int a, int b, int c) class Printer { // fields public void printBook(String bookName) { // … } public void printBook(String bookName, int numberOfPages) { // … } } class Printer { // fields public void printBook(String bookName) {…
Read More Method Overloading in Javaclass ClassName { data member; method(); } class Vehicle { // data members/fields String brand; int maxSpeed; // constructor public Vehicle() { // body of the constructor } // method public void printMaxSpeed() { // body of the method } // instance initializer code block { System.out.println(“This is a code block!”); } } class Test…
Read More Objects and Classes in JavaName Convention Class name It should start with a capital letter and be a noun e.g. String, Color, Button, System, Thread, etc. Interface name It should start with a capital letter and be an adjective e.g. Runnable, Remote, ActionListener, etc. Method name It should start with a lowercase letter and be a verb e.g. actionPerformed (), main (),…
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