JAVA LAMBDA EXPRESSION

Java lambda expressions are a powerful feature introduced in Java 8 that allows us to write more concise and expressive code. A lambda expression is essentially a way to define an anonymous function, which can be treated as a value and passed around in our code.

To create a lambda expression in Java, we follow this syntax:

(parameters) -> expression

or

(parameters) -> { statements }

The parameters represent the input to the function, and the expression or statements represent the body of the function. The arrow operator "->" separates the parameters from the body of the lambda expression.

Here's an example to illustrate how to create a lambda expression:

// Lambda expression with a single parameter

Function<Integer, Integer> square = x -> x * x;

// Lambda expression with multiple parameters

BiFunction<Integer, Integer, Integer> sum = (x, y) -> x + y;

// Lambda expression with no parameters

Supplier<String> message = () -> "Hello, World!";

// Lambda expression with multiple statements

Consumer<String> printer = (name) -> {

    System.out.println("Hello, " + name);

    System.out.println("Welcome to Java!");

};

// Using lambda expressions

int result = square.apply(5); // result = 25

int sumResult = sum.apply(10, 20); // sumResult = 30

String msg = message.get(); // msg = "Hello, World!"

printer.accept("John"); // prints "Hello, John" and "Welcome to Java!"

In the above example, we create lambda expressions for different functional interfaces like `Function`, 'BiFunction', 'Supplier', and 'Consumer'. We can then use these lambda expressions to perform operations like squaring a number, calculating the sum of two numbers, retrieving a message, and printing a name.

Lambda expressions provide a concise and expressive way to write code, making our programs more readable and maintainable. They are particularly useful when working with functional interfaces, which are interfaces that have a single abstract method. We can use lambda expressions to implement the abstract method of a functional interface without having to define a separate class.