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Diffstat (limited to 'csharp.html.markdown')
| -rw-r--r-- | csharp.html.markdown | 161 |
1 files changed, 95 insertions, 66 deletions
diff --git a/csharp.html.markdown b/csharp.html.markdown index df6544d3..1d7d0881 100644 --- a/csharp.html.markdown +++ b/csharp.html.markdown @@ -1,5 +1,5 @@ --- -language: c# +language: C# contributors: - ["Irfan Charania", "https://github.com/irfancharania"] - ["Max Yankov", "https://github.com/golergka"] @@ -12,22 +12,24 @@ contributors: filename: LearnCSharp.cs --- -C# is an elegant and type-safe object-oriented language that enables developers to build a variety of secure and robust applications that run on the .NET Framework. +C# is an elegant and type-safe object-oriented language that enables developers to build a variety of secure and robust applications that run on the cross-platform .NET framework. -[Read more here.](http://msdn.microsoft.com/en-us/library/vstudio/z1zx9t92.aspx) +[Read more here.](https://docs.microsoft.com/en-us/dotnet/csharp/tour-of-csharp/) ```c# // Single-line comments start with // + /* Multi-line comments look like this */ + /// <summary> /// This is an XML documentation comment which can be used to generate external /// documentation or provide context help within an IDE /// </summary> /// <param name="firstParam">This is some parameter documentation for firstParam</param> /// <returns>Information on the returned value of a function</returns> -//public void MethodOrClassOrOtherWithParsableHelp(string firstParam) {} +public void MethodOrClassOrOtherWithParsableHelp(string firstParam) { } // Specify the namespaces this source code will be using // The namespaces below are all part of the standard .NET Framework Class Library @@ -46,6 +48,10 @@ using System.Data.Entity; // Namespaces define scope to organize code into "packages" or "modules" // Using this code from another source file: using Learning.CSharp; + +// You can also do this in C# 10, it is called file-scoped namespaces. +// namespace Learning.CSharp; + namespace Learning.CSharp { // Each .cs file should at least contain a class with the same name as the file. @@ -152,7 +158,7 @@ on a new line! ""Wow!"", the masses cried"; // Arrays - zero indexed // The array size must be decided upon declaration - // The format for declaring an array is follows: + // The format for declaring an array is // <datatype>[] <var name> = new <datatype>[<array size>]; int[] intArray = new int[10]; @@ -166,7 +172,7 @@ on a new line! ""Wow!"", the masses cried"; // Lists // Lists are used more frequently than arrays as they are more flexible - // The format for declaring a list is follows: + // The format for declaring a list is // List<datatype> <var name> = new List<datatype>(); List<int> intList = new List<int>(); List<string> stringList = new List<string>(); @@ -176,14 +182,14 @@ on a new line! ""Wow!"", the masses cried"; // Lists don't default to a value; // A value must be added before accessing the index intList.Add(1); - Console.WriteLine("intList @ 0: " + intList[0]); + Console.WriteLine("intList at 0: " + intList[0]); - // Others data structures to check out: + // Other data structures to check out: // Stack/Queue // Dictionary (an implementation of a hash map) // HashSet // Read-only Collections - // Tuple (.Net 4+) + // Tuple (.NET 4+) /////////////////////////////////////// // Operators @@ -216,20 +222,20 @@ on a new line! ""Wow!"", the masses cried"; | Bitwise inclusive OR */ - // Incrementations + // Incrementing int i = 0; - Console.WriteLine("\n->Inc/Dec-rementation"); - Console.WriteLine(i++); //Prints "0", i = 1. Post-Incrementation - Console.WriteLine(++i); //Prints "2", i = 2. Pre-Incrementation - Console.WriteLine(i--); //Prints "2", i = 1. Post-Decrementation - Console.WriteLine(--i); //Prints "0", i = 0. Pre-Decrementation + Console.WriteLine("\n->Inc/Dec-rement"); + Console.WriteLine(i++); //Prints "0", i = 1. Post-Increment + Console.WriteLine(++i); //Prints "2", i = 2. Pre-Increment + Console.WriteLine(i--); //Prints "2", i = 1. Post-Decrement + Console.WriteLine(--i); //Prints "0", i = 0. Pre-Decrement /////////////////////////////////////// // Control Structures /////////////////////////////////////// Console.WriteLine("\n->Control Structures"); - // If statements are c-like + // If statements are C-like int j = 10; if (j == 10) { @@ -254,7 +260,7 @@ on a new line! ""Wow!"", the masses cried"; int fooWhile = 0; while (fooWhile < 100) { - //Iterated 100 times, fooWhile 0->99 + // Iterated 100 times, fooWhile 0->99 fooWhile++; } @@ -273,25 +279,25 @@ on a new line! ""Wow!"", the masses cried"; } while (fooDoWhile < 100); - //for loop structure => for(<start_statement>; <conditional>; <step>) + // for loop structure => for(<start_statement>; <conditional>; <step>) for (int fooFor = 0; fooFor < 10; fooFor++) { - //Iterated 10 times, fooFor 0->9 + // Iterated 10 times, fooFor 0->9 } // For Each Loop // foreach loop structure => foreach(<iteratorType> <iteratorName> in <enumerable>) // The foreach loop loops over any object implementing IEnumerable or IEnumerable<T> - // All the collection types (Array, List, Dictionary...) in the .Net framework + // All the collection types (Array, List, Dictionary...) in the .NET framework // implement one or both of these interfaces. // (The ToCharArray() could be removed, because a string also implements IEnumerable) foreach (char character in "Hello World".ToCharArray()) { - //Iterated over all the characters in the string + // Iterated over all the characters in the string } // Switch Case - // A switch works with the byte, short, char, and int data types. + // A switch works with byte, short, char, and int data types. // It also works with enumerated types (discussed in Enum Types), // the String class, and a few special classes that wrap // primitive types: Character, Byte, Short, and Integer. @@ -310,7 +316,7 @@ on a new line! ""Wow!"", the masses cried"; break; // You can assign more than one case to an action // But you can't add an action without a break before another case - // (if you want to do this, you would have to explicitly add a goto case x + // (if you want to do this, you would have to explicitly add a goto case x) case 6: case 7: case 8: @@ -329,18 +335,27 @@ on a new line! ""Wow!"", the masses cried"; // Convert String To Integer // this will throw a FormatException on failure - int.Parse("123");//returns an integer version of "123" + int.Parse("123"); // returns an integer version of "123" - // try parse will default to type default on failure - // in this case: 0 + // TryParse will default to the type's default value on failure + // in this case 0 int tryInt; if (int.TryParse("123", out tryInt)) // Function is boolean Console.WriteLine(tryInt); // 123 // Convert Integer To String - // Convert class has a number of methods to facilitate conversions + // The Convert class has a number of methods to facilitate conversions + + // String to int + + // Better + bool result = int.TryParse(string, out var integer) + int.Parse(string); + + // Not recommended Convert.ToString(123); - // or + + // Int to string tryInt.ToString(); // Casting @@ -373,7 +388,10 @@ on a new line! ""Wow!"", the masses cried"; Console.Read(); } // End main method - // CONSOLE ENTRY A console application must have a main method as an entry point + // Available in C# 9 and later, this is basically syntactic sugar for a class. Records are immutable*. + public record ARecord(string Csharp); + + // CONSOLE ENTRY - A console application must have a main method as an entry point public static void Main(string[] args) { OtherInterestingFeatures(); @@ -404,13 +422,13 @@ 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 + // 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 } // GENERICS // The classes for TKey and TValue is specified by the user calling this function. - // This method emulates the SetDefault of Python + // This method emulates Python's dict.setdefault() public static TValue SetDefault<TKey, TValue>( IDictionary<TKey, TValue> dictionary, TKey key, @@ -552,7 +570,7 @@ on a new line! ""Wow!"", the masses cried"; } // PARALLEL FRAMEWORK - // http://blogs.msdn.com/b/csharpfaq/archive/2010/06/01/parallel-programming-in-net-framework-4-getting-started.aspx + // https://devblogs.microsoft.com/csharpfaq/parallel-programming-in-net-framework-4-getting-started/ var words = new List<string> {"dog", "cat", "horse", "pony"}; @@ -564,11 +582,11 @@ on a new line! ""Wow!"", the masses cried"; } ); - //Running this will produce different outputs - //since each thread finishes at different times. - //Some example outputs are: - //cat dog horse pony - //dog horse pony cat + // Running this will produce different outputs + // since each thread finishes at different times. + // Some example outputs are: + // cat dog horse pony + // dog horse pony cat // DYNAMIC OBJECTS (great for working with other languages) dynamic student = new ExpandoObject(); @@ -651,10 +669,10 @@ on a new line! ""Wow!"", the masses cried"; return ++count; } - // A delegate is a reference to a method + // A delegate is a reference to a method. // To reference the Increment method, - // first declare a delegate with the same signature - // ie. takes no arguments and returns an int + // first declare a delegate with the same signature, + // i.e. takes no arguments and returns an int public delegate int IncrementDelegate(); // An event can also be used to trigger delegates @@ -725,10 +743,10 @@ on a new line! ""Wow!"", the masses cried"; int _speed; // Everything is private by default: Only accessible from within this class. // can also use keyword private public string Name { get; set; } - + // Properties also have a special syntax for when you want a readonly property // that simply returns the result of an expression - public string LongName => Name + " " + _speed + " speed"; + public string LongName => Name + " " + _speed + " speed"; // Enum is a value type that consists of a set of named constants // It is really just mapping a name to a value (an int, unless specified otherwise). @@ -742,7 +760,7 @@ on a new line! ""Wow!"", the masses cried"; Gitane // 43 } // We defined this type inside a Bicycle class, so it is a nested type - // Code outside of this class should reference this type as Bicycle.Brand + // Code outside of this class should reference this type as Bicycle.BikeBrand public BikeBrand Brand; // After declaring an enum type, we can declare the field of this type @@ -865,7 +883,7 @@ on a new line! ""Wow!"", the masses cried"; } } - //Method to display the attribute values of this Object. + // Method to display the attribute values of this Object. public virtual string Info() { return "Gear: " + Gear + @@ -960,7 +978,7 @@ on a new line! ""Wow!"", the masses cried"; /// <summary> /// Used to connect to DB for LinqToSql example. /// EntityFramework Code First is awesome (similar to Ruby's ActiveRecord, but bidirectional) - /// http://msdn.microsoft.com/en-us/data/jj193542.aspx + /// https://docs.microsoft.com/ef/ef6/modeling/code-first/workflows/new-database /// </summary> public class BikeRepository : DbContext { @@ -1069,7 +1087,7 @@ on a new line! ""Wow!"", the masses cried"; { private static bool LogException(Exception ex) { - /* log exception somewhere */ + // log exception somewhere return false; } @@ -1089,7 +1107,7 @@ on a new line! ""Wow!"", the masses cried"; // Spell failed return false; } - // Other exceptions, or MagicServiceException where Code is not 42 + // Other exceptions, or MagicServiceException where Code is not 42 catch(Exception ex) when (LogException(ex)) { // Execution never reaches this block @@ -1117,12 +1135,12 @@ on a new line! ""Wow!"", the masses cried"; [Obsolete("Use NewMethod instead", false)] public static void ObsoleteMethod() { - /* obsolete code */ + // obsolete code } public static void NewMethod() { - /* new code */ + // new code } public static void Main() @@ -1154,9 +1172,9 @@ namespace Learning.More.CSharp } } -//New C# 7 Feature -//Install Microsoft.Net.Compilers Latest from Nuget -//Install System.ValueTuple Latest from Nuget +// New C# 7 Feature +// Install Microsoft.Net.Compilers Latest from Nuget +// Install System.ValueTuple Latest from Nuget using System; namespace Csharp7 { @@ -1213,7 +1231,7 @@ namespace Csharp7 Console.WriteLine(tt.GetLastName()); } } - + // PATTERN MATCHING class PatternMatchingTest { @@ -1297,26 +1315,37 @@ namespace Csharp7 ``` ## Topics Not Covered +✨ New, 👍 Old, 🎈 LTS, 🔥 Cross-platform, 🎁 Windows-only * Attributes - * async/await + + * Asynchronous Programming + * Web Development - * ASP.NET MVC & WebApi (new) - * ASP.NET Web Forms (old) - * WebMatrix (tool) + * ASP.NET Core ✨ + * Desktop Development - * Windows Presentation Foundation (WPF) (new) - * Winforms (old) + * Windows Presentation Foundation 👍 🎈 🎁 + * Universal Windows Platform ✨ 🎁 + * Uno Platform 🔥 ✨ + * WinForms 👍 🎈 🎁 + * Avalonia 🔥 ✨ + * WinUI ✨ 🎁 + +* Cross-platform Development + * Xamarin.Forms 👍 + * MAUI ✨ + ## Further Reading + * [C# language reference](https://docs.microsoft.com/dotnet/csharp/language-reference/) + * [Learn .NET](https://dotnet.microsoft.com/learn) + * [C# Coding Conventions](https://docs.microsoft.com/en-us/dotnet/csharp/programming-guide/inside-a-program/coding-conventions) * [DotNetPerls](http://www.dotnetperls.com) * [C# in Depth](http://manning.com/skeet2) - * [Programming C#](http://shop.oreilly.com/product/0636920024064.do) - * [LINQ](http://shop.oreilly.com/product/9780596519254.do) - * [MSDN Library](http://msdn.microsoft.com/en-us/library/618ayhy6.aspx) - * [ASP.NET MVC Tutorials](http://www.asp.net/mvc/tutorials) - * [ASP.NET Web Matrix Tutorials](http://www.asp.net/web-pages/tutorials) - * [ASP.NET Web Forms Tutorials](http://www.asp.net/web-forms/tutorials) + * [Programming C# 5.0](http://shop.oreilly.com/product/0636920024064.do) + * [LINQ Pocket Reference](http://shop.oreilly.com/product/9780596519254.do) * [Windows Forms Programming in C#](http://www.amazon.com/Windows-Forms-Programming-Chris-Sells/dp/0321116208) - * [C# Coding Conventions](http://msdn.microsoft.com/en-us/library/vstudio/ff926074.aspx) + * [freeCodeCamp - C# Tutorial for Beginners](https://www.youtube.com/watch?v=GhQdlIFylQ8) + |