protected Object clone() throws CloneNotSupportedException class ClassA implements Cloneable { private int someNum; private ClassC nestedObjectReference; @Override public Object clone() throws CloneNotSupportedException { return super.clone(); } // getter and setter methods } class ClassC { private String classData; public ClassC(String classData) { this.classData = classData; } // getter and setter methods } public class Test…
Read More Object Cloning in Javapublic sealed class Vehicle permits Car, Truck, Bus {} final class Bus extends Vehicle { } non-sealed class Truck extends Account { } sealed class Car permits BlueCar, RedCar{ } public abstract sealed class User permits PremiumUser, AdvancedUser { public abstract String getUserData(); } non-sealed class PremiumUser extends User { @Override public String getUserData() {…
Read More Sealed Classes and Interfaces in Javaclass Test { public static void main(String[] args) { String name = null; System.out.println(name.toUpperCase()); } } Output: Exception in thread “main” java.lang.NullPointerException at com.example.Test.main (Test.java:9) Here, we got an error message that the NPE has occurred on line 9. Unfortunately, we can’t conclude which value exactly was null from the message. class Test { public static…
Read More Helpful NullPointerExceptions (NPE) in Javaclass Test { public static void main(String[] args) { Vehicle vehicle = new Car(); if (vehicle instanceof Car) { Car car = (Car) vehicle; car.openTrunk(); // other code … } else if (vehicle instanceof Truck) { Truck truck = (Truck) vehicle; truck.removeTrailer(); // other code … } } } class Test { public static void…
Read More Java Pattern Matching for instanceofclass User { private String name; private String username; private String membershipType; private String address; public User(String name, String username, String membershipType, String address) { this.name = name; this.username = username; this.membershipType = membershipType; this.address = address; } public String getName() { return name; } public void setName(String name) { this.name = name; } public…
Read More Java Recordsclass Test { public static void main(String[] args) { String color = “blue”; switch (color) { case “white”: System.out.println(“The color is white.”); break; case “yellow”: System.out.println(“The color is yellow.”); break; case “blue”: System.out.println(“The color is blue.”); break; case “green”: System.out.println(“The color is green.”); break; default: System.out.println(“Unrecognized color!”); } } } Output: The color is blue.…
Read More Java Switch ExpressionsString multilineText= “”” Hi, this is one simple example of a multiline text”””; class Test { public static void main(String[] args) { String example = “{\”key1\”:\”value1\”,\”key2\”:” + “\”value2\”,\”key3\”:\”value3\”}”; System.out.println(example); } } Output: {“key1″:”value1″,”key2″:”value2″,”key3″:”value3”} Now, let’s use a Text Block: class Test { public static void main(String[] args) { String example = “”” { “key1”:…
Read More Java Text Blocks