Java Articles - Page 193 of 745

This class matches punctuation marks. i.e.!"#$%&'()*+, -./:;?@[\]^_`{|}~Example 1 Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class AlphanumericExample {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a string");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       //Regular expression       String regex = "[\p{Punct}]";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0; ... Read More

ToDoubleFunction is a functional interface defined in java.util.function package. This functional interface expects a parameter as input and produces a double-valued result. It is used as an assignment target for a lambda expression or method reference. ToDoubleFunction interface contains only one abstract method, applyAsDouble().Syntax@FunctionalInterface public interface ToDoubleFunction {    double applyAsDouble(T value); }Example-1import java.util.function.ToDoubleFunction; public class ToDoubleFunctionTest1 {    public static void main(String args[]) {       ToDoubleFunction strLength = s -> s.length();    // lambda expression       System.out.println("The length of a given String using lambda expression is: " + strLength.applyAsDouble("TutorialsPoint"));       ToDoubleFunction innerClassImplementation = new ToDoubleFunction() ... Read More

This class matches alpha numeric characters.Example  Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class AlphanumericExample {    public static void main(String args[]) {       //Reading String from user       System.out.println("Enter a string");       Scanner sc = new Scanner(System.in);       String input = sc.nextLine();       //Regular expression       String regex = "[\p{Alnum}]";       //Compiling the regular expression       Pattern pattern = Pattern.compile(regex);       //Retrieving the matcher object       Matcher matcher = pattern.matcher(input);       int count = 0;     ... Read More

In this article, we will learn about the POSIX character classes p{Digit} Java regex. First, will know about \p{Digit} and the use of \p{Digit} along with examples. What is \p{Digit}? In Java regex, the \p{Digit} is a POSIX (Portable Operating System Interface) character class in Java regular expressions that matches any decimal digit character. This class matches decimal digits from 0 to 9.  The \p{Digit} is also equivalent to other expressions in Java: "\d": Follows the same POSIX standards. "[0-9]": For ASCII digits only. How to Use \p{Digit} in Java? We can use the ... Read More

The Runnable interface is a functional interface defined in java.lang package. This interface contains a single abstract method, run() with no arguments. When an object of a class implementing this interface used to create a thread, then run() method has invoked in a thread that executes separately.Syntax@FunctionalInterface public interface Runnable {  void run(); }In the below example, we can implement a Runnable interface by using an anonymous class and lambda expression.Examplepublic class RunnableLambdaTest {    public static void main(String[] args) {       Runnable r1 = new Runnable() {          @Override          public void run() { // anonymous class   ... Read More

This class matches alphabetic characters both upper case and smaller case.Example 1 Live Demoimport java.util.Scanner; import java.util.regex.Matcher; import java.util.regex.Pattern; public class Example {    public static void main( String args[] ) {       //Regular expression to match lower case letters       String regex = "^\p{Alpha}+$";       //Getting the input data       Scanner sc = new Scanner(System.in);       System.out.println("Enter 5 input strings: ");       String input[] = new String[5];       for (int i=0; i

In this article, we will learn about the p{ASCII} of the POSIX character class in Java regex. What is \p{ASCII}? In Java regex, \p{ASCII} POSIX character class matches any of the characters that fall within ASCII. ASCII (American Standard Code for Information Interchange) defines a character encoding standard consisting of 128 characters (0-127). This class matches the ASCII characters within the range of \x00-\x7F. Printable characters in the \p{ASCII} of the Java Regex are: Numbers (0 to 9) Uppercase letters (A to Z) Lowercase letters (a ... Read More

JavaFX Button class provides the setOnAction() method that can be used to set an action for the button click event. An EventHandler is a functional interface and holds only one method is the handle() method.Syntax@FunctionalInterface public interface EventHandler extends EventListenerIn the below example, we can able to implement event handling of JavaFX by using a lambda expression.Exampleimport javafx.application.*; import javafx.beans.property.*; import javafx.event.*; import javafx.scene.*; import javafx.scene.control.*; import javafx.scene.layout.*; import javafx.stage.*; public class LambdaWithJavaFxTest extends Application {    public static void main(String[] args) {       Application.launch(args);    }    @Override    public void start(Stage stage) throws Exception {     ... Read More

The DoubleFunction is a built-in functional interface defined in java.util.function package. This interface accepts one double-valued parameter as input and returns a value of type R. As this is a functional interface, it can be used as an assignment target for a lambda expression or method reference. DoubleFunction interface having only one abstract method, apply().Syntax@FunctionalInterface public interface DoubleFunction {  R apply(double value); }Exampleimport java.util.function.DoubleFunction; public class DoubleFunctionTest {    public static void main(String[] args) {       DoubleFunction getGrade = marks -> { // lambda expression          if(marks > 90 && marks 70 && marks 50 && marks

A prime number is a number that is greater than 1 and divided by 1 or itself only. It other words, it can't be divided by other numbers than itself or 1. The generation of prime numbers is 2, 3, 5, 7, 11, 13, 17 and etc.In the below example, we can generate the prime numbers with the help of Stream API and lambda expressions.Exampleimport java.util.*; import java.util.stream.*; public class PrimeNumberLambdaTest {    public static void main(String[] args) {       List generate = PrimeNumberLambdaTest.generate(10);       System.out.println(generate);    }    public static List generate(int series) {       Set set = new TreeSet(); ... Read More