Lambda Expressions java 8

Lambda expressions are a feature introduced in Java 8 that allow functional programming in Java. They provide a concise way to represent functional interfaces (interfaces with only one abstract method) using an expression.

For example, consider the following functional interface for a single method that takes two integers as inputs and returns an integer: 

@FunctionalInterface

public interface MathOperation {

   int operation(int a, int b);

}

A lambda expression can be used to implement this functional interface, such as the following addition operation:

MathOperation addition = (int a, int b) -> a + b;

Here, the lambda expression (int a, int b) -> a + b implements the operation method of the MathOperation functional interface. The expression takes two integer inputs a and b and returns their sum.

Lambda expressions can be used to pass behavior as a method argument, for example, with a method that takes a MathOperation argument and applies it to two integer inputs:

public static int operate(int a, int b, MathOperation mathOperation) {

   return mathOperation.operation(a, b);

}

This method can be called with a lambda expression, such as:

int result = operate(1, 2, (a, b) -> a + b);

 In this example, the lambda expression (a, b) -> a + b is passed as an argument to the operate method, which applies the operation method to 1 and 2 and returns 3.