import java.util.Scanner;

public class MethodsLec {

public static void main(String[] args) {

Scanner input = new Scanner(System.in);

validateCurrency(input);

countdownRecursion(10);

countdown();

System.out.println(sayHello("Fernando", "Mendoza"));

System.out.println(sayHello());

System.out.println("sum() " + sum(1, 2));

System.out.println("decimal sum() " + sum(3.4, 6.7));

System.out.println("sayHello() = " + sayHello("Douglas"));

System.out.println();

}

public static String sayHello(){

return "Hello world";

}

public static String sayHello(String name){

return "Hello " + name;

}

public static String sayHello(String firstName, String lastName){

return "Hello " + firstName + " " + lastName;

}

public static int sum(int num1, int num2){

return num1 + num2;

}

public static double sum(double num1, double num2){

return num1 + num2;

}

// counting from 5 to 1 using a loop

public static void countdown(){

for (byte x = 5; x >= 0 ;x--){

System.out.println("for loop = " + x);

}

}

// n a variable number

public static void countdownRecursion(int n){

System.out.println("recursion = " + n);

// how to stop

if(n < 1){

return;

}

// how to proceed

n = n - 1;

// how to try again with new data

countdownRecursion(n);

}

// that only looks for $

public static void validateCurrency(Scanner scan){

System.out.println("Give me an amount: ");

String amount = scan.nextLine();

// how to stop

if(amount.startsWith("$")){

System.out.println("It's valid money format");

return;

}

// how to proceed, how to run process again?

System.out.println("Invalid money format, try again");

validateCurrency(scan);

}

}