A lambda expression is an anonymous function without having any name and does not belong to any class that means it is a block of code that can be passed around to execute.Syntax(parameter-list) -> {body}We can implement a lambda expression without creating an anonymous inner class in the below program. For the button's ActionListener interface, we need to override one abstract method addActionListener() and implement the block of code using the lambda expression.Exampleimport java.awt.*; import java.awt.event.*; import javax.swing.*; public class LambdaExpressionButtonTest extends JFrame {    private JButton btn;    public LambdaExpressionButtonTest() {       btn = new JButton("Click on the button"); ... Read More

Anonymous class is an inner class without a name, which means that we can declare and instantiate class at the same time. A lambda expression is a short form for writing an anonymous class. By using a lambda expression, we can declare methods without any name.Anonymous class vs Lambda ExpressionAn anonymous class object generates a separate class file after compilation that increases the size of a jar file while a lambda expression is converted into a private method. It uses invokedynamic bytecode instruction to bind this method dynamically, which saves time and memory.We use this keyword to represent the current class in lambda expression while in the ... Read More

The lambda expressions are introduced in Java 8. It is one of the most popular features of Java 8 and brings functional programming capabilities to Java. By using a lambda expression, we can directly write the implementation for a method in Java.In the below program, we can create a thread by implementing the Runnable interface using lamda expression. While using the lambda expressions, we can skip the new Runnable() and run() method because the compiler knows that Thread object takes a Runnable object and that contains only one method run() that takes no argument.Examplepublic class LambdaThreadTest {    public static void main(String args[]) {     ... Read More

Yes, any lambda expression is an object in Java. It is an instance of a functional interface. We have assigned a lambda expression to any variable and pass it like any other object.Syntax(parameters) -> expression              or (parameters) -> { statements; }In the below example, how a lambda expression has assigned to a variable and how it can be invoked.Example@FunctionalInterface interface ComparatorTask {    public boolean compare(int t1, int t2); } public class LambdaObjectTest {    public static void main(String[] args) {       ComparatorTask ctask = (int t1, int t2) -> {return t1 ... Read More

A lambda expression is an anonymous method and doesn't execute on its own in java. Instead, it is used to implement a method defined by the functional interface. A lambda expression used with any functional interface and Comparator is a functional interface. The Comparator interface has used when sorting a collection of objects compared with each other.In the below example, we can sort the employee list by name using the Comparator interface.Exampleimport java.util.ArrayList; import java.util.Collections; import java.util.List; class Employee {    int id;    String name;    double salary;    public Employee(int id, String name, double salary) {       super();   ... Read More

There are different scoping rules for lambda expression in Java. In lambda expressions, this and super keywords are lexically scoped means that this keyword refers to the object of the enclosing type and the super keyword refers to the enclosing superclass. In the case of an anonymous class, they are relative to the anonymous class itself. Similarly, local variables declared in lambda expression conflicts with variables declared in the enclosing class. In the case of an anonymous class, they are allowed to shadow variables in the enclosing class.Example@FunctionalInterface interface TestInterface {    int calculate(int x, int y); } class Test {    public ... Read More

The lambda expressions are easy and contain three parts like parameters (method arguments), arrow operator (->) and expressions (method body). The lambda expressions can be categorized into three types: no parameter lambda expressions, single parameter lambda expressions and multiple parameters lambda expressions.Lambda Expression with no parameterWe need to create no parameter lambda expression then start the expression with empty parenthesis.Syntax() -> {    //Body of no parameter lambda }Example(no parameter Lambda)import java.util.function.*; import java.util.Random; public class LambdaExpression1 {    public static void main(String args[]) {       NumberUtil num = new NumberUtil();       int randVal = num.getRandomValue(       ... Read More

A lambda block states that lambda expression with multiple statements. It expands the type of operations to perform with a lambda expression. The multiple statements containing bodies are called expression bodies. A lambda expression with expression bodies is called expression lambdas. Whenever we are using expression lambdas, explicitly use a return statement to return a value.Exampleinterface NumberFinder {    int finder(int number1, int number2); } public class LambdaNumberFinder {    public static void main(String args[]) {       NumberFinder numberFinder = (number1, number2) -> {          int temp = 0;          if(number1 > number2) ... Read More

The lambda expressions are anonymous functions and don't have any return type, access modifier and not belonging to any class. It can be used to simplify the implementation of the abstract method in a functional interface. Whenever there is a functional interface, we can use lambda expressions instead of anonymous inner classes.Syntax([comma seperated argument-list]) -> {body}Example@FunctionalInterface interface BonusCalculator {    public double calcBonus(int amount); } class EmpDetails {    public void getBonus(BonusCalculator calculator, int amount) {       double bonus = calculator.calcBonus(amount);       System.out.println("Bonus: " + bonus);    } } public class LambdaExpressionTest {    public static void main(String[] ... Read More

The lambda expressions have a very simple, precise syntax and provide flexibility to specify the datatypes for the function parameters. Its return type is a parameter -> expression body to understand the syntax, we can divide it into three parts.Parameters : These are function method parameters and match with the signature of a function defined in the functional interface. Defining the data-type of parameters is optional but the number of parameters can match with the defined signatures in the interface.Expression Body : This is either a single statement or collection of statements that represent the function definition. Defining the data-type for return ... Read More