Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
Articles by raja
Page 5 of 38
Can we define an abstract class with no abstract methods in Java?
Yes, we can declare an abstract class with no abstract methods in Java. An abstract class means that hiding the implementation and showing the function definition to the user. An abstract class having both abstract methods and non-abstract methods. For an abstract class, we are not able to create an object directly. But Indirectly we can create an object using the subclass object. A Java abstract class can have instance methods that implement a default behavior. An abstract class can extend only one class or one abstract class at a time. Declaring a class as abstract with no abstract methods means that we don't allow it ...
Read MoreCan we have a try block without a catch block in Java?
Yes, It is possible to have a try block without a catch block by using a final block. As we know, a final block will always execute even there is an exception occurred in a try block, except System.exit() it will execute always. Example 1 public class TryBlockWithoutCatch { public static void main(String[] args) { try { System.out.println("Try Block"); } finally { System.out.println("Finally Block"); } } } Output Try Block Finally Block A ...
Read MoreHow can we read a JSON file in Java?
The JSON is one of the widely used data-interchange formats and is a lightweight and language independent. The json.simple is a lightweight JSON processing library that can be used to read and write JSON files and it can be used to encode or decode JSON text and fully compliant with JSON specification (RFC4627). In order to read a JSON file, we need to download the json-simple.jar file and set the path to execute it.json fileExampleimport java.io.*; import java.util.*; import org.json.simple.*; import org.json.simple.parser.*; public class JSONReadFromTheFileTest { public static void main(String[] args) { JSONParser parser = new JSONParser(); try { ...
Read MoreHow to implement LongToIntFunction using lambda and method reference in Java?
LongToIntFunction is a functional interface from java.util.function package introduced in Java 8. This functional interface accepts a long-valued parameter as input and produces an int-valued result. LongToIntFunction interface can be used as an assignment target for a lambda expression or method reference. This interface contains only one abstract method: applyAsInt() and doesn't contain any default and abstract methods.Syntax@FunctionalInterface interface LongToIntFunction { int applyAsInt(long value); }Example of Lambda Expressionimport java.util.function.LongToIntFunction; public class LongToIntLambdaTest { public static void main(String args[]) { LongToIntFunction getInt = longVal -> { ...
Read MoreHow to implement LongToDoubleFunction using lambda and method reference in Java?
LongToDoubleFunction is a built-in functional interface and part of java.util.function package. This functional interface accepts a long-valued parameter as input and produces a double-valued result. LongToDoubleFunction can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsDouble().Syntax@FunctionalInterface interface LongToDoubleFunction { double applyAsDouble(long value); }Example of Lambda Exampleimport java.util.function.LongToDoubleFunction; public class LongToDoubleLambdaTest { public static void main(String args[]) { LongToDoubleFunction getDouble = longVal -> { // lambda expression double doubleVal = longVal; ...
Read MoreHow to implement IntToLongFunction using lambda and method reference in Java?
IntToLongFunction is a built-in functional interface from java.util.function package. This functional interface accepts an int-valued parameter and produces a long-valued result. IntToLongFunction interface can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsLong().Syntax@FunctionalInterface interface IntToLongFunction { long applyAsLong(int value); }Example of Lambda Expressionimport java.util.function.IntToLongFunction; public class IntToLongFunctionLambdaTest { public static void main(String args[]) { IntToLongFunction getLong = intVal -> { // lambda expression long ...
Read MoreHow to implement IntToDoubleFunction using lambda and method reference in Java?
IntToDoubleFunction is a functional interface from java.util.function package. This functional interface accepts an int-valued argument and produces a double-valued result. IntToDoubleFunction can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsDouble().Syntax@FunctionalInterface interface IntToDoubleFunction { double applyAsDouble(int value); }Example of Lambda Expressionimport java.util.function.IntToDoubleFunction;; public class IntToDoubleLambdaTest { public static void main(String[] args) { IntToDoubleFunction getDouble = intVal -> { // lambda expression double ...
Read MoreHow to implement DoubleToIntFunction using lambda expression in Java?
DoubleToIntFunction is a functional interface defined in java.util.function package introduced in Java 8 version. This functional interface accepts a double-valued argument and produces an int-valued result. DoubleToIntFunction interface can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsInt().Syntax@FunctionalInterface interface DoubleToIntFunction { int applyAsInt(double value) }Exampleimport java.util.function.DoubleToIntFunction; public class DoubleToIntFunctionTest { public static void main(String args[]) { DoubleToIntFunction test = doubleVal -> { // lambda expression ...
Read MoreHow to implement DoubleToLongFunction using lambda expression in Java?
DoubleToLongFunction is a built-in functional interface from java.util.function package introduced in Java 8. This functional interface accepts a double-valued parameter and produces a long-valued result. DoubleToLongFunction interface can be used as an assignment target for a lambda expression or method reference. It contains only one abstract method: applyAsLong().Syntax@FunctionalInterface public interface DoubleToLongFunction { long applyAsLong(double value) }Exampleimport java.util.function.DoubleToLongFunction; public class DoubleToLongFunctionTest { public static void main(String args[]) { double dbl = 30.1212; DoubleToLongFunction castToLong = (dblValue) -> (long) dblValue; // lambda expression ...
Read MoreHow to declare a variable within lambda expression in Java?
A lambda expression is a function that expects and accepts input parameters and produces output results. It is an instance of a functional interface and also known as a single abstract method interface (SAM interface) like Runnable, Comparator, Callable and etc. We can declare a variable as a final string[] array and able to access that array index within a lambda expression.Exampleimport java.util.*; public class LambdaTest { public static void main(String args[]) { final String[] country = {null}; List cities = new ArrayList(); ...
Read More