diff options
Diffstat (limited to 'csharp.html.markdown')
| -rw-r--r-- | csharp.html.markdown | 92 |
1 files changed, 82 insertions, 10 deletions
diff --git a/csharp.html.markdown b/csharp.html.markdown index 02650038..7d7f4340 100644 --- a/csharp.html.markdown +++ b/csharp.html.markdown @@ -6,6 +6,8 @@ contributors: - ["Melvyn Laïly", "http://x2a.yt"] - ["Shaun McCarthy", "http://www.shaunmccarthy.com"] - ["Wouter Van Schandevijl", "http://github.com/laoujin"] + - ["Jo Pearce", "http://github.com/jdpearce"] + - ["Chris Zimmerman", "https://github.com/chriszimmerman"] filename: LearnCSharp.cs --- @@ -43,8 +45,8 @@ using System.Data.Entity; // Using this code from another source file: using Learning.CSharp; namespace Learning.CSharp { - // Each .cs file should at least contain a class with the same name as the file - // you're allowed to do otherwise, but shouldn't for sanity. + // Each .cs file should at least contain a class with the same name as the file. + // You're allowed to do otherwise, but shouldn't for sanity. public class LearnCSharp { // BASIC SYNTAX - skip to INTERESTING FEATURES if you have used Java or C++ before @@ -159,7 +161,7 @@ on a new line! ""Wow!"", the masses cried"; // List<datatype> <var name> = new List<datatype>(); List<int> intList = new List<int>(); List<string> stringList = new List<string>(); - List<int> z = new List<int> { 9000, 1000, 1337 }; // intialize + List<int> z = new List<int> { 9000, 1000, 1337 }; // initialize // The <> are for generics - Check out the cool stuff section // Lists don't default to a value; @@ -393,6 +395,7 @@ on a new line! ""Wow!"", the masses cried"; ref int maxCount, // Pass by reference out int count) { + //the argument passed in as 'count' will hold the value of 15 outside of this function count = 15; // out param must be assigned before control leaves the method } @@ -418,12 +421,48 @@ on a new line! ""Wow!"", the masses cried"; // Item is an int Console.WriteLine(item.ToString()); } + + // YIELD + // Usage of the "yield" keyword indicates that the method it appears in is an Iterator + // (this means you can use it in a foreach loop) + public static IEnumerable<int> YieldCounter(int limit = 10) + { + for (var i = 0; i < limit; i++) + yield return i; + } + + // which you would call like this : + public static void PrintYieldCounterToConsole() + { + foreach (var counter in YieldCounter()) + Console.WriteLine(counter); + } + + // you can use more than one "yield return" in a method + public static IEnumerable<int> ManyYieldCounter() + { + yield return 0; + yield return 1; + yield return 2; + yield return 3; + } + + // you can also use "yield break" to stop the Iterator + // this method would only return half of the values from 0 to limit. + public static IEnumerable<int> YieldCounterWithBreak(int limit = 10) + { + for (var i = 0; i < limit; i++) + { + if (i > limit/2) yield break; + yield return i; + } + } public static void OtherInterestingFeatures() { // OPTIONAL PARAMETERS MethodSignatures(3, 1, 3, "Some", "Extra", "Strings"); - MethodSignatures(3, another: 3); // explicity set a parameter, skipping optional ones + MethodSignatures(3, another: 3); // explicitly set a parameter, skipping optional ones // BY REF AND OUT PARAMETERS int maxCount = 0, count; // ref params must have value @@ -443,6 +482,9 @@ on a new line! ""Wow!"", the masses cried"; // ?? is syntactic sugar for specifying default value (coalesce) // in case variable is null int notNullable = nullable ?? 0; // 0 + + // ?. is an operator for null-propagation - a shorthand way of checking for null + nullable?.Print(); // Use the Print() extension method if nullable isn't null // IMPLICITLY TYPED VARIABLES - you can let the compiler work out what the type is: var magic = "magic is a string, at compile time, so you still get type safety"; @@ -588,7 +630,7 @@ on a new line! ""Wow!"", the masses cried"; public static class Extensions { - // EXTENSION FUNCTIONS + // EXTENSION METHODS public static void Print(this object obj) { Console.WriteLine(obj.ToString()); @@ -610,7 +652,7 @@ on a new line! ""Wow!"", the masses cried"; { return _cadence; } - set // set - define a method to set a proprety + set // set - define a method to set a property { _cadence = value; // Value is the value passed in to the setter } @@ -750,7 +792,7 @@ on a new line! ""Wow!"", the masses cried"; // It's also possible to define custom Indexers on objects. // All though this is not entirely useful in this example, you - // could do bicycle[0] which yields "chris" to get the first passenger or + // could do bicycle[0] which returns "chris" to get the first passenger or // bicycle[1] = "lisa" to set the passenger. (of this apparent quattrocycle) private string[] passengers = { "chris", "phil", "darren", "regina" }; @@ -761,7 +803,7 @@ on a new line! ""Wow!"", the masses cried"; } set { - return passengers[i] = value; + passengers[i] = value; } } @@ -837,7 +879,8 @@ on a new line! ""Wow!"", the masses cried"; bool Broken { get; } // interfaces can contain properties as well as methods & events } - // Class can inherit only one other class, but can implement any amount of interfaces + // Class can inherit only one other class, but can implement any amount of interfaces, however + // the base class name must be the first in the list and all interfaces follow class MountainBike : Bicycle, IJumpable, IBreakable { int damage = 0; @@ -870,13 +913,42 @@ on a new line! ""Wow!"", the masses cried"; public DbSet<Bicycle> Bikes { get; set; } } + + // Classes can be split across multiple .cs files + // A1.cs + public partial class A + { + public static void A1() + { + Console.WriteLine("Method A1 in class A"); + } + } + + // A2.cs + public partial class A + { + public static void A2() + { + Console.WriteLine("Method A2 in class A"); + } + } + + // Program using the partial class "A" + public class Program + { + static void Main() + { + A.A1(); + A.A2(); + } + } } // End Namespace ``` ## Topics Not Covered * Attributes - * async/await, yield, pragma directives + * async/await, pragma directives * Web Development * ASP.NET MVC & WebApi (new) * ASP.NET Web Forms (old) |