//Classes and Delegates are always reference types
//Structs are value types
static void Main(string[] args)
{
Module03BasicTypesAndConstructs.Coffee firstBean = new Module03BasicTypesAndConstructs.Coffee(5, "Good Beans", "My Place");
firstBean.OutOfBeans += new Inventory().HandleOutOfBeans;
DrinksMachine dm = new DrinksMachine
{
Age = 2,
Model = "BeanSmasher 3000",
Make = "Fourth Coffee"
};
for (int x = 0; x < 4; x++)
{
dm.MakeCappuccino(ref firstBean);
}
DrinksMachine dm2 = new DrinksMachine(2);
DrinksMachine dm3 = new DrinksMachine("Fourth Coffee", "BeanDestroyer 3000");
DrinksMachine dm4 = new DrinksMachine(3, "Fourth Coffee", "BeanToaster Turbo");
//Boxing is converting a value type to a reference type by wrapping it in an object
int i = 100;
object obj = i;
// Unboxing is converting a reference type to a value type and you must explicitly cast the variable back to its original type
int j;
j = (int)obj;
double weightInKilos = 80;
double weightInPounds = Conversions.KilosToPounds(weightInKilos);
//Using IComparer implentation to sort coffee by rating rather than Variety (default set by coffee class IComparable implentation)
//Coffee Class (rather than coffee struct above)
Coffee coffeenew1 = new Coffee();
coffeenew1.AverageRating = 4.5;
Coffee coffeenew2 = new Coffee();
coffeenew2.AverageRating = 8.1;
Coffee coffeenew3 = new Coffee();
coffeenew3.AverageRating = 7.1;
//Add the instances to arraylist
ArrayList coffeList = new ArrayList();
coffeList.Add(coffeenew1);
coffeList.Add(coffeenew2);
coffeList.Add(coffeenew3);
//Sort arraylist by average rating(passed custom Icomparer implentation)
coffeList.Sort(new CoffeeRatingComparer());
foreach (Coffee drink in coffeList)
{
Console.WriteLine(drink.AverageRating);
}
Console.ReadLine();
}
static void Main(string[] args)
{
#region Enums
//Set enum variable by name or value
Day favoriteDay = Day.Friday;
// is equivalent to
Day favoriteDay1 = (Day)6;
Console.WriteLine($"{favoriteDay} via Day.Friday and {favoriteDay1} via (Day)6.");
#endregion
#region structs
//instantiating a struct without constructor
Coffee coffee1 = new Coffee
{
Strength = 3,
Bean = "Arabica",
CountryOfOrigin = "Columbia"
};
Coffee coffee2 = new Coffee(5, "Antigua Volcanic", "Guetemala");
//Accessing a public array in a struct
PublicMenu myMenu = new PublicMenu("cocoa");
string firstDrink = myMenu.beverages[0];
Console.WriteLine(firstDrink);
//Accessing a value in a private array via indexer
Menu myPrivateMenu = new Menu("YooHoo", "Screwdriver");
string firstPrivateDrink = myPrivateMenu[0];
int numberOfChoices = myPrivateMenu.Length;
Console.WriteLine($"The first private drink is {firstPrivateDrink} which I accessed via an indexer and the number of beverages to choose is {numberOfChoices}.");
#endregion
#region Collections
//Collections are multiple items of the same time stored in a variable
//List store linear collections of items
//Dictionary store collections of key/value pairs
//Queue store items in a FIFO collection
//Stack store items in a LIFO collection
//Core Operations of collections: Add items, remove items, retrieve specific items, count items, iterate through collection(one at a time)
#region List collection
ArrayList beverages = new ArrayList();
//Items are implicitly cast to the object type when you add them
beverages.Add(coffee1);
beverages.Add(coffee2);
//retrieve items by index
//Items must be explicitly cast back to their original type
Coffee firstCoffee = (Coffee)beverages[0];
Coffee secondCoffee = (Coffee)beverages[1];
Console.WriteLine(firstCoffee + " " + secondCoffee);
//foreach loop to iterate over collection
foreach (Coffee c in beverages)
{
Console.WriteLine(c.CountryOfOrigin);
}
#endregion
#region Dictionary Collection
//Create a new hashtable collection
Hashtable ingredients = new Hashtable();
// Add some key/value pairs to the collection
ingredients.Add("Cafe au Lait", "Coffee, Milk");
ingredients.Add("Cafe Mocha", "Coffee, Milk, Chocolate");
ingredients.Add("Cappuccino", "Coffee, Milk, Foam");
ingredients.Add("Irish Coffee", "Coffee, Whiskey, Cream, Sugar");
ingredients.Add("Macchiato", "Coffee, Milk, Foam");
//Check whether a key exists.
if (ingredients.ContainsKey("Cafe Mocha"))
{
// Retrieve the value associated with a key.
Console.WriteLine("the ingredients of a cafe mocha are: {0}", ingredients["Cafe Mocha"]);
}
// dictionary classes actually contain two enumerable collections so you can iterate over either of these collections
// although it is usually the keys you iterate over to retrieve the values
foreach (string key in ingredients.Keys)
{
// For Each key, retrieve the value associated with the key.
Console.WriteLine("The ingredients of a {0} are {1}", key, ingredients[key]);
}
#endregion
#region Querying a Collection
//LINQ expressions
// from <variable names> in <data source>
// where <selection criteria>
// orderby <result ordering criteria>
// select <variable names>
// Can also use: FirstOrDefault, Last, Max, and Min after the query above (use dot notation on the variable name(s)
// Create a new hashtable with drinks and prices
Hashtable prices = new Hashtable();
prices.Add("Cafe au Lait", 1.99M);
prices.Add("Caffe Americano", 1.89M);
prices.Add("Cafe Mocha", 2.99M);
prices.Add("Cappuccino", 2.49M);
prices.Add("Espresso", 1.49M);
prices.Add("Espresso Romana", 1.59M);
prices.Add("English Tea", 1.69M);
prices.Add("Juice", 2.89M);
// Select all the drinks that cost les than $2.00 and order them by cost.
var bargains =
from string drink in prices.Keys
where (Decimal)prices[drink] < 2.00M
orderby prices[drink] ascending
select drink;
// Display the results
foreach (string bargain in bargains)
{
Console.WriteLine("{0} costs {1}", bargain, prices[bargain]);
}
#endregion
#endregion
#region Handling Events
// Delegates are reference to Methods
// They can be saved as field and passed as parameter
//They allow one to execute code that is provided from external sources
//Delegates can be executed exactly like methods
//Delegates first parameter is the object that raised the event
//Second parameter is the event arguments that much be an instance of EventArgs or an instance of a class that derives from EventArgs
// events wrap delegates like a property wraps a field
// Allow the class to notify other consumers of actions performed within it.
// An event may only be raised by it's containing class
Inventory myInventory = new Inventory();
coffee2.OutOfBeans += myInventory.HandleOutOfBeans;
for (int i = 0; i < 9; i++)
{
coffee2.MakeCoffee();
}
#endregion
Console.ReadLine();
}
