2- Lamda Expression

 What is Lamda expression and its need?

Lambda Expressions were added in Java 8.

A lambda expression is a short block of code which takes in parameters and returns a value.

 Lambda expressions are similar to methods, but they do not need a name and they can be implemented right in the body of a method.

OR

Expression through which we can represent anonymous(nameless) function.

Syntax: 

( argument-list )   ->  {body} 

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

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

 Body : It contains expressions and statements for lambda expression. 

WRITE A PIECE OF JAVA CODE USING LAMDA EXPRESSION

/*

--> 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

 

 Write a code using two interfaces similar in working but

 --> Use anonymous class to implement first interface  &

 --> Use lambda expression to implement another interface

 */

package com.company;

interface Run{

    void speed(int a);

   

}

interface Walk{

    void walking(int b);

}

public class AdvanceJava_AnonymousClass_LambdaExpression {

    public static void main(String[] args) {

   

    //Using Anonymous Class without lambda expression

      Walk w= new Walk() {  

             public void walking(int b) {

             System.out.println("You are running at: "+b+" m/s");

              }

        };

    w.walking(2);  

         

       

    //Using Anonymous Class WITH lambda expression  

    Run r1 = (a)->{System.out.println("You are running at: "+a+" m/s");};

   

     r1.speed(13);

   

   

    }

}