Selection Statements

Here is the code for our selection examples

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace SelectionExamples
{
    class Program
    {
        /*This program provides examples of
         * if statements and switches
         * Steve Conger 10/11/2016*/

        static void Main(string[] args)
        {
            int number;
            Console.WriteLine("Enter number");
            //try parse returns a boolean (true/false)
            //if the number is good it assigns it to the variable
            //outside the method (out)

            bool goodNumber = int.TryParse(Console.ReadLine(),out number);

            if(goodNumber == false)
            {
                Console.WriteLine("restart and enter a valid integer");
                Console.WriteLine("Press any key to exit");
                Console.ReadKey();
                return; //ends the program
            }

            // >, <, >=, <=, ==, != (not equal)
            //with strings it is often best to use .Equals
            if (number > 10)
            {
                Console.WriteLine("the number is greater than 10");
            }
            else if(number==10)
            {
                Console.WriteLine("the number is 10");
            }
            else
            {
                Console.WriteLine("The number is less than 10");
            }

            Console.WriteLine("Enter the name of the current month");
            string month = Console.ReadLine();
            // || or , && and

            if(month.Equals("October") || month.Equals("october"))
            {
                Console.WriteLine("Happy Halloween");

            }
            else
            {
                Console.WriteLine("You are a bit confused");
            }


            //switch statement
            int choice;
            Console.WriteLine("Enter an integer between 1 and 4");
            bool good = int.TryParse(Console.ReadLine(), out choice);
            //!good same as good !== true or good == false
            if(!good)
            {
                return;
            }

            //switch statement
            switch(choice)
            {
                case 1:
                    Console.WriteLine("You entered 1");
                    break;
                case 2: //fall through to three
                case 3:
                    Console.WriteLine("You chose 2 or 3");
                    break;
                case 4:
                    Console.WriteLine("You entered 4");
                    break;
                default://captures anything else
                    Console.WriteLine("Not a valid choice");
                    break;
            }

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();


            
        }
    }
}

here is the code for the birthday program

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Birthdate
{
    class Program
    {
        static void Main(string[] args)
        {
            DateTime birthday;
            DateTime today = DateTime.Now;
            int age;
            
            
            
            //you can try parse for DateTime as well
            Console.WriteLine("enter your birth date");
            bool goodDate = DateTime.TryParse(Console.ReadLine(), out birthday);

            if (!goodDate)
            {
                Console.WriteLine("enter a valid birth date");
                bool good = DateTime.TryParse(Console.ReadLine(), out birthday);
                //nested if statement
                if(!good) //give a second chance
                {
                    Console.WriteLine("Sorry still not valid");
                    Console.WriteLine("Press any key to exit");
                    Console.ReadKey();
                    return;
                }//end inner if

            }//end outer if
            //just subtract years. We could also do months and days
            age = today.Year - birthday.Year;
            Console.WriteLine("You are {0} years old", age);

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();
        }//end main
    }//end program class
}//end namespace

Here is a solution for the peer excercise

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace PeerIf
{
    class Program
    {
        static void Main(string[] args)
        {
            string password = "P@ssw0rd1";
            string username = "customer";
            string user;
            string pass;

            Console.WriteLine("Enter your user name");
            user = Console.ReadLine();

            Console.WriteLine("Enter your password");
            pass = Console.ReadLine();

            if(password.Equals(pass) && username.Equals(user))
            {
                Console.WriteLine("Welcome user");
            }
            else
            {
                Console.WriteLine("invalid password or user name");
            }

            /*an alternative way
             * if(username.Equals(user)
             * {
             *     if(password.Equals(pass)
             *     {
             *         Console.WriteLine("Welcome");
             *     }
             *     else
             *     {
             *          Console.WriteLIne("Inavalid");
             *     }

             * }
             * */

            Console.WriteLine("Press any key to exit");
            Console.ReadKey();





        }
    }
}