cs11dotnet7/vs4win/Chapter05/PeopleApp/Program.cs

using Packt.Shared;

Thread.CurrentThread.CurrentCulture = 
  System.Globalization.CultureInfo.GetCultureInfo("en-GB");

// Person bob = new Person(); // C# 1.0 or later
// var bob = new Person(); // C# 3.0 or later

Person bob = new(); // C# 9.0 or later
WriteLine(bob.ToString());

bob.Name = "Bob Smith";
bob.DateOfBirth = new DateTime(1965, 12, 22); // C# 1.0 or later

WriteLine(format: "{0} was born on {1:dddd, d MMMM yyyy}",
  arg0: bob.Name,
  arg1: bob.DateOfBirth);

Person alice = new()
{
  Name = "Alice Jones",
  DateOfBirth = new(1998, 3, 7) // C# 9.0 or later
};

WriteLine(format: "{0} was born on {1:dd MMM yy}",
  arg0: alice.Name,
  arg1: alice.DateOfBirth);

bob.FavoriteAncientWonder = WondersOfTheAncientWorld.StatueOfZeusAtOlympia;

WriteLine(
  format: "{0}'s favorite wonder is {1}. Its integer is {2}.",
  arg0: bob.Name,
  arg1: bob.FavoriteAncientWonder,
  arg2: (int)bob.FavoriteAncientWonder);

bob.BucketList =
  WondersOfTheAncientWorld.HangingGardensOfBabylon
  | WondersOfTheAncientWorld.MausoleumAtHalicarnassus;

// bob.BucketList = (WondersOfTheAncientWorld)18;

WriteLine($"{bob.Name}'s bucket list is {bob.BucketList}");

bob.Children.Add(new Person { Name = "Alfred" }); // C# 3.0 and later
bob.Children.Add(new() { Name = "Zoe" }); // C# 9.0 and later

WriteLine($"{bob.Name} has {bob.Children.Count} children:");

for (int childIndex = 0; childIndex < bob.Children.Count; childIndex++)
{
  WriteLine($"> {bob.Children[childIndex].Name}");
}

/*
foreach (Person child in bob.Children)
{
  WriteLine($"> {child.Name}");
}
*/

BankAccount.InterestRate = 0.012M; // store a shared value

BankAccount jonesAccount = new();
jonesAccount.AccountName = "Mrs. Jones";
jonesAccount.Balance = 2400;
WriteLine(format: "{0} earned {1:C} interest.",
  arg0: jonesAccount.AccountName,
  arg1: jonesAccount.Balance * BankAccount.InterestRate);

BankAccount gerrierAccount = new();
gerrierAccount.AccountName = "Ms. Gerrier";
gerrierAccount.Balance = 98;
WriteLine(format: "{0} earned {1:C} interest.",
  arg0: gerrierAccount.AccountName,
  arg1: gerrierAccount.Balance * BankAccount.InterestRate);

WriteLine($"{bob.Name} is a {Person.Species}");

WriteLine($"{bob.Name} was born on {bob.HomePlanet}");

Person blankPerson = new();

WriteLine(format:
  "{0} of {1} was created at {2:hh:mm:ss} on a {2:dddd}.",
  arg0: blankPerson.Name,
  arg1: blankPerson.HomePlanet,
  arg2: blankPerson.Instantiated);

Person gunny = new(initialName: "Gunny", homePlanet: "Mars");

WriteLine(format:
  "{0} of {1} was created at {2:hh:mm:ss} on a {2:dddd}.",
  arg0: gunny.Name,
  arg1: gunny.HomePlanet,
  arg2: gunny.Instantiated);

bob.WriteToConsole();
WriteLine(bob.GetOrigin());

(string, int) fruit = bob.GetFruit();
WriteLine($"{fruit.Item1}, {fruit.Item2} there are.");

var fruitNamed = bob.GetNamedFruit();
WriteLine($"There are {fruitNamed.Number} {fruitNamed.Name}.");

var thing1 = ("Neville", 4);
WriteLine($"{thing1.Item1} has {thing1.Item2} children.");

var thing2 = (bob.Name, bob.Children.Count);
WriteLine($"{thing2.Name} has {thing2.Count} children.");

(string fruitName, int fruitNumber) = bob.GetFruit();
WriteLine($"Deconstructed: {fruitName}, {fruitNumber}");

// Deconstructing a Person
var (name1, dob1) = bob; // implicitly calls the Deconstruct method
WriteLine($"Deconstructed: {name1}, {dob1}");

var (name2, dob2, fav2) = bob;
WriteLine($"Deconstructed: {name2}, {dob2}, {fav2}");

WriteLine(bob.SayHello());
WriteLine(bob.SayHello("Emily"));

WriteLine(bob.OptionalParameters());

WriteLine(bob.OptionalParameters("Jump!", 98.5));

WriteLine(bob.OptionalParameters(number: 52.7, command: "Hide!"));

WriteLine(bob.OptionalParameters("Poke!", active: false));

int a = 10;
int b = 20;
int c = 30;
WriteLine($"Before: a = {a}, b = {b}, c = {c}");
bob.PassingParameters(a, ref b, out c);
WriteLine($"After: a = {a}, b = {b}, c = {c}");

int d = 10;
int e = 20;
WriteLine($"Before: d = {d}, e = {e}, f doesn't exist yet!");

// simplified C# 7.0 or later syntax for the out parameter 
bob.PassingParameters(d, ref e, out int f);
WriteLine($"After: d = {d}, e = {e}, f = {f}");

Person sam = new()
{
  Name = "Sam",
  DateOfBirth = new(1969, 6, 25)
};

WriteLine(sam.Origin);
WriteLine(sam.Greeting);
WriteLine(sam.Age);

sam.FavoriteIceCream = "Chocolate Fudge";
WriteLine($"Sam's favorite ice-cream flavor is {sam.FavoriteIceCream}.");

string color = "Black";

try
{
  sam.FavoritePrimaryColor = color;
  WriteLine($"Sam's favorite primary color is {sam.FavoritePrimaryColor}.");
}
catch (Exception ex)
{
  WriteLine("Tried to set {0} to '{1}': {2}",
    nameof(sam.FavoritePrimaryColor), color, ex.Message);
}

/*
Book book = new()
{
  Isbn = "978-1803237800",
  Title = "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals"
};
*/
Book book = new(isbn: "978-1803237800",
  title: "C# 11 and .NET 7 - Modern Cross-Platform Development Fundamentals")
{
  Author = "Mark J. Price",
  PageCount = 821
};

WriteLine("{0}: {1} written by {2} has {3:N0} pages.",
  book.Isbn, book.Title, book.Author, book.PageCount);

sam.Children.Add(new() { Name = "Charlie", DateOfBirth = new(2010, 3, 18) });
sam.Children.Add(new() { Name = "Ella", DateOfBirth = new(2020, 12, 24) });

// get using Children list
WriteLine($"Sam's first child is {sam.Children[0].Name}.");
WriteLine($"Sam's second child is {sam.Children[1].Name}.");

// get using integer position indexer
WriteLine($"Sam's first child is {sam[0].Name}.");
WriteLine($"Sam's second child is {sam[1].Name}.");

// get using name indexer
WriteLine($"Sam's child named Ella is {sam["Ella"].Age} years old.");

// Implementing functionality using methods

Person lamech = new() { Name = "Lamech" };
Person adah = new() { Name = "Adah" };
Person zillah = new() { Name = "Zillah" };

lamech.Marry(adah);
// Person.Marry(zillah, lamech);

if (zillah + lamech)
{
  WriteLine($"{zillah.Name} and {lamech.Name} successfully got married.");
}
else
{
  WriteLine($"{zillah.Name} and {lamech.Name} failed to marry.");
}

lamech.OutputSpouses();
adah.OutputSpouses();
zillah.OutputSpouses();

// call instance method
Person baby1 = lamech.ProcreateWith(adah);
baby1.Name = "Jabal";
WriteLine($"{baby1.Name} was born on {baby1.DateOfBirth}");

// call static method
Person baby2 = Person.Procreate(zillah, lamech);
baby2.Name = "Tubalcain";

// use operator to "multiply"
Person baby3 = lamech * adah;
baby3.Name = "Jubal";

Person baby4 = zillah * lamech;
baby4.Name = "Naamah";

WriteLine($"{lamech.Name} has {lamech.Children.Count} children.");
WriteLine($"{adah.Name} has {adah.Children.Count} children.");
WriteLine($"{zillah.Name} has {zillah.Children.Count} children.");

for (int i = 0; i < lamech.Children.Count; i++)
{
  WriteLine(format: "{0}'s child #{1} is named \"{2}\".",
    arg0: lamech.Name, arg1: i, arg2: lamech[i].Name);
}

// Implementing functionality using local functions

int number = 6; // change to -1 to make the exception handling code execute

try
{
  WriteLine($"{number}! is {Person.Factorial(number)}");
}
catch (Exception ex)
{
  WriteLine($"{ex.GetType()} says: {ex.Message} number was {number}.");
}

// Pattern matching with objects

Passenger[] passengers = {
  new FirstClassPassenger { AirMiles = 1_419, Name = "Suman" },
  new FirstClassPassenger { AirMiles = 16_562, Name = "Lucy" },
  new BusinessClassPassenger { Name = "Janice" },
  new CoachClassPassenger { CarryOnKG = 25.7, Name = "Dave" },
  new CoachClassPassenger { CarryOnKG = 0, Name = "Amit" },
};

foreach (Passenger passenger in passengers)
{
  decimal flightCost = passenger switch
  {
    /* C# 8 syntax
    FirstClassPassenger p when p.AirMiles > 35000 => 1500M,
    FirstClassPassenger p when p.AirMiles > 15000 => 1750M,
    FirstClassPassenger                           => 2000M, */

    // C# 9 or later syntax
    FirstClassPassenger p => p.AirMiles switch
    {
      > 35000 => 1500M,
      > 15000 => 1750M,
      _       => 2000M
    },
    BusinessClassPassenger _                      => 1000M,
    CoachClassPassenger p when p.CarryOnKG < 10.0 => 500M,
    CoachClassPassenger _                         => 650M,
    _                                             => 800M
  };
  WriteLine($"Flight costs {flightCost:C} for {passenger}");
}

ImmutablePerson jeff = new()
{
  FirstName = "Jeff",
  LastName = "Winger"
};
// We cannot set the properties after initialization because they
// are init-only.
// jeff.FirstName = "Geoff";

ImmutableVehicle car = new()
{
  Brand = "Mazda MX-5 RF",
  Color = "Soul Red Crystal Metallic",
  Wheels = 4
};

ImmutableVehicle repaintedCar = car
  with { Color = "Polymetal Grey Metallic" };

WriteLine($"Original car color was {car.Color}.");
WriteLine($"New car color is {repaintedCar.Color}.");

ImmutableAnimal oscar = new("Oscar", "Labrador");
var (who, what) = oscar; // calls Deconstruct method 
WriteLine($"{who} is a {what}.");