Lambda Expression in JAVA

-> The Lambda expression is used to provide the implementation of an interface which has functional interface.

->  It saves a lot of code.

-> In case of lambda expression, we don't need to define the method again for providing the implementation. Here, we just write the implementation code.

-> Java lambda expression is treated as a function, so compiler does not create .class file.



Functional Interface

-> Lambda expression provides implementation of functional interface.

-> An interface which has only one abstract method is called functional interface.

-> Java provides an anotation @FunctionalInterface, which is used to declare an interface as functional interface.


Syntax

(argument-list) -> {body}


Java lambda expression is consisted of three components.

1) Argument-list: It can be empty or non-empty as well.

2) Arrow-token: It is used to link arguments-list and body of expression.

3) Body: It contains expressions and statements for lambda expression.



Example :  Addition of two numbers using lamda expression

@FunctionalInterface
interface Calc{

   int add(int n1,int n2);

}




public class Calculation{
 
 
    public static void main(String[] args) { 

     
       Calc addition=(n1,n2)->{

          return n1+n2;
       };
   
 
       System.out.println("Addition "+addition.add(10,20)); 


       
 }


}


Output

Addition 30