### JAVA Code Review: Best Practices ###
https://www.java-success.com/30-java-code-review-checklist-items/

### JAVA Design Principles ###
https://stackify.com/solid-design-principles/

###==### JAVA_8 Features: Java 8 In Action ###==###
Why Lambda? Functional Programming

What is Lambda? Fuctional vs Object Oriented
> A function that doesn’t have a name and doesn’t belong to any class.

//Syntax of lambda expression
(parameter_list) -> {function_body}

A lambda expression in Java has these main parts: Lambda expression only has body and parameter list.
1. No name – function is anonymous so we don’t care about the name
2. Parameter list
3. Body – This is the main part of the function.
4. No return type – The java 8 compiler is able to infer the return type by checking the code. 

Why Functional Programming? "Passing Behavior: Behavior Parameterization"
[Previous: Behavior is associated with an Object/Class.]

Example: Greeting Behavior: public void greet(.....Behavior.....)  // Pass the interface Greeting: perform()

> HindiGreeting, EnglishGreeting etc. // JAVA 7 way: Polymorphism in Action // 

> Here we are a passing a thing that have the behavior, not the behavior //***//

How Lambda? "Functions in Isolation" and Treated as values. [Function as a Value]

ablockOfCode= public void perform(){Syso("Hello World");}
            = () -> {Syso("Hello World");}

> greet( () -> Syso("Hindi Greeting") ) // JAVA 8 : Passing behavior directly //

===== CONCEPTS ======

greetingFunction= () -> Syso("Hindi Greeting");
addFunction= (int a, int b) -> a+b;   

1. Type of Lambda expression? == "Functional Interface" 
2. Lambda vs Interface Implemenation = 
3. Lambda vs Anonymous Class = 

4. Type Inference? StringLengthLambda lambda= (String s) -> { s.length(); } === s -> s.length(); // Type-I // 

5. Exception Handling in lambda
6. Closures in lambda:= Comes in picture if we uses the scoped variable in Lambda-Expression, they freeze.

7. Method References:: Another way to use 

############ Stream API Examples: http://www.java2novice.com/java-8/streams/ #############

CONCEPT: Collection of 6 Cars need some action:- Paint, fix the engine, fix the tires 

By using streams we can perform various aggregate operations on the data returned from collections, 
arrays, Input/Output operations. 

Create a stream()  ---> Perform a intermediate operation[filter()] ----> then perform terminal operation [count()]

# map() vs flatMap() #
MAP: it applies a function on each element of stream and stores the value returned by the function into a new Stream. 


##### OPTIONAL in java.util package #####
It is used to represent a value is present or absent. This class has various utility methods to facilitate code
to handle values as ‘available’ or ‘not available’ instead of checking null values.