Payment Process using an Interface:
===================================
==> here this application developing with four modules.
==> module ==> a java file
	1) interface.java
	2) implementClass1.java
	3) implementClass2.java	
	4) MainClass.java

1) interface.java
==================

package Interface.IO.Java.Pack;

public interface PayementProcess {
	String processPayment(double amount);
	boolean paymentStatus(String txId);
}

2) implementClass1.java
=======================
package Interface.IO.Java.Pack;

import java.util.Random;

public class PaypalProcessor implements PayementProcess {

	@Override
	public String processPayment(double amount) {
		if(amount <= 0) {
			return "ppnull101";
		}
		else {
			return "pp" + new Random().nextInt(10000);
		}
	}

	@Override
	public boolean paymentStatus(String txId) {
		if(txId.startsWith("ppnull")) {
			return false;
		}
		else {
			return true;
		}
	}

3) implementClass2.java
========================
package Interface.IO.Java.Pack;

import java.util.Random;

public class StripeProcessor implements PayementProcess {

	@Override
	public String processPayment(double amount) {
		if(amount <= 0) {
			return "spnull101";
		}
		else {
			return "sp" + new Random().nextInt(10000);
		}
	}

	@Override
	public boolean paymentStatus(String txId) {
		if(txId.startsWith("spnull")) {
			return false;
		}
		else {
			return true;
		}
	}

}



}

4) MainClass.java
==================
package Interface.IO.Java.Pack;

public class MainClass {

	public static void main(String[] args) {
		// creating the object for PaypalProcessor
		PaypalProcessor paypal = new PaypalProcessor();
		double amount = 10000.0;
		
		if(paypal.paymentStatus(paypal.processPayment(amount))) {
			System.out.println(amount + ": paid through paypal.");
		}
		else {
			System.out.println(amount + " : is invalid.");
		}
//		System.out.println("=====================================");
		String line = "=".repeat(50);
		System.out.println(line);
		
		StripeProcessor stripe = new StripeProcessor();
		double fund = 19999.0;
		
		if(stripe.paymentStatus(stripe.processPayment(fund))) {
			System.out.println(fund+" : paid through stripe process.");
		}
		else {
			System.out.println(fund+" : is invalid");
		}
	}

}
==============================================================
Anonymous Inner Class:
======================
What is anonymous?
===================

package JavaDemo.IO.Pack;

class ClassA{
	void m1() {
		System.out.println("Hello");
	}
}

public class MainClass {

	public static void main(String[] args) {
		ClassA ca = new ClassA(); // named object
		ca.m1();
		
		new ClassA().m1(); // anonymous object or nameless object
	}

}

Note:
=====
==> If a class with only one method, we can be instantiated with nameless ==> Anonymous object.
==> If a class with more than one method, we can be instantiated with named object.

Anonymous Inner Class:
======================

interface MyInter{
	void f1();
	void f2();
}
class Demo{
	void m1(MyInter mi){
	}
}
public class Test{
	public static void main(String[] args)
	{
		Demo demo = new Demo();
		demo.m1(new MyInter(){
			public void f1(){
			}
			public void f2(){
			});
	}
}

==> when without implements the class if we can create an object for interface reference in a class is called as "Anonymous class"
=======================================================
Method Parameter Passing Techniques:
====================================
1) pass by value technique:
===========================
class ClassA{
	def m1(int x)
	{
		x = x + 20;
	}
}

public MainClass{
	public static void main(String[] args){
		ClassA ca = new ClassA();
		int p = 100;
		ca.m1(p);
		System.out.println(p);
	}
}

2) Pass by Reference:
======================

class Item{
	double price;
}

class ClassA{
	void increment(Item item){
		item.price = item.price + 2000.0;
	}
}

public class MainClass{
	public static void main(String[] args)
	{
		ClassA ca = new ClassA();
		Item it = new Item();

		it.price = 5000.0;
		ca.increment(it.price);
		System.out.println(it.price);
		
	}
}
==============================================================
class Item{
	double price;
}

class ClassA{
	void increment(Item item){
		Item it = new Item();
		item.price = item.price + 2000.0;
	}
}

public class MainClass{
	public static void main(String[] args)
	{
		ClassA ca = new ClassA();
		Item it = new Item();

		it.price = 5000.0;
		ca.increment(it.price);
		System.out.println(it.price);
		
	}
}