Tutorial by Examples: l

When passing formal arguments to a generic method, relevant generic type arguments can usually be inferred implicitly. If all generic type can be inferred, then specifying them in the syntax is optional. Consider the following generic method. It has one formal parameter and one generic type paramet...

Type constraints are able to force a type parameter to implement a certain interface or class. interface IType; interface IAnotherType; // T must be a subtype of IType interface IGeneric<T> where T : IType { } // T must be a subtype of IType class Generic<T> where T...

It is possible to specify whether or not the type argument should be a reference type or a value type by using the respective constraints class or struct. If these constraints are used, they must be defined before all other constraints (for example a parent type or new()) can be listed. // TRef mus...

Every method has a unique signature consisting of a accessor (public, private, ...) ,optional modifier (abstract), a name and if needed method parameters. Note, that the return type is not part of the signature. A method prototype looks like the following: AccessModifier OptionalModifier ReturnTyp...

Calling a static method: // Single argument System.Console.WriteLine("Hello World"); // Multiple arguments string name = "User"; System.Console.WriteLine("Hello, {0}!", name); Calling a static method and storing its return value: string input = System.Con...

You can use default parameters if you want to provide the option to leave out parameters: static void SaySomething(string what = "ehh") { Console.WriteLine(what); } static void Main() { // prints "hello" SaySomething("hello"); // prints &quot...

The yield keyword is used to define a function which returns an IEnumerable or IEnumerator (as well as their derived generic variants) whose values are generated lazily as a caller iterates over the returned collection. Read more about the purpose in the remarks section. The following example has a...

You can extend the functionality of existing yield methods by passing in one or more values or elements that could define a terminating condition within the function by calling a yield break to stop the inner loop from executing. public static IEnumerable<int> CountUntilAny(int start, HashSet...

class Program { static void Main(string[] args) { // Run 2 Tasks. var task1 = Task.Run(() => PerformAction(1))); var task2 = Task.Run(() => PerformAction(2))); // Wait (i.e. block this thread) until both Tasks are complete. Task.WaitA...

6.0 As of C# 6.0, the await keyword can now be used within a catch and finally block. try { var client = new AsyncClient(); await client.DoSomething(); } catch (MyException ex) { await client.LogExceptionAsync(); throw; } finally { await client.CloseAsync(); } 5.06.0 P...

1 - Create an empty folder, it will contain the files created in the next steps. 2 - Create a file named project.json with the following content (adjust the port number and rootDirectory as appropriate): { "dependencies": { "Microsoft.AspNet.Server.Kestrel": "1.0.0...

Developers can be caught out by the fact that type inference doesn't work for constructors: class Tuple<T1,T2> { public Tuple(T1 value1, T2 value2) { } } var x = new Tuple(2, "two"); // This WON'T work... var y = new Tuple<int, string>(2, "t...

Typically lambdas are used for defining simple functions (generally in the context of a linq expression): var incremented = myEnumerable.Select(x => x + 1); Here the return is implicit. However, it is also possible to pass actions as lambdas: myObservable.Do(x => Console.WriteLine(x)); ...

An iterator method is not executed until the return value is enumerated. It's therefore advantageous to assert preconditions outside of the iterator. public static IEnumerable<int> Count(int start, int count) { // The exception will throw when the method is called, not when the result i...

Use parentheses around the expression to the left of the => operator to indicate multiple parameters. delegate int ModifyInt(int input1, int input2); ModifyInt multiplyTwoInts = (x,y) => x * y; Similarly, an empty set of parentheses indicates that the function does not accept parameters. ...

Unlike an expression lambda, a statement lambda can contain multiple statements separated by semicolons. delegate void ModifyInt(int input); ModifyInt addOneAndTellMe = x => { int result = x + 1; Console.WriteLine(result); }; Note that the statements are enclosed in braces {}. ...

For null values: Nullable<int> i = null; Or: int? i = null; Or: var i = (int?)null; For non-null values: Nullable<int> i = 0; Or: int? i = 0;

int? i = null; if (i != null) { Console.WriteLine("i is not null"); } else { Console.WriteLine("i is null"); } Which is the same as: if (i.HasValue) { Console.WriteLine("i is not null"); } else { Console.WriteLine("i is null&quot...

Given following nullable int int? i = 10; In case default value is needed, you can assign one using null coalescing operator, GetValueOrDefault method or check if nullable int HasValue before assignment. int j = i ?? 0; int j = i.GetValueOrDefault(0); int j = i.HasValue ? i.Value : 0; The ...

See RFC 2030 for details on the SNTP protocol. using System; using System.Globalization; using System.Linq; using System.Net; using System.Net.Sockets; class SntpClient { const int SntpPort = 123; static DateTime BaseDate = new DateTime(1900, 1, 1); static void Main(string[...