Tutorial by Examples: re

using System; using System.IO; using System.Net; using System.Net.Sockets; using System.Text; class TcpChat { static void Main(string[] args) { if(args.Length == 0) { Console.WriteLine("Basic TCP chat"); Console.WriteLine(); ...

string sqrt = "\u221A"; // √ string emoji = "\U0001F601"; // 😁 string text = "\u0022Hello World\u0022"; // "Hello World" string variableWidth = "\x22Hello World\x22"; // "Hello World"

// assign string from a string literal string s = "hello"; // assign string from an array of characters char[] chars = new char[] { 'h', 'e', 'l', 'l', 'o' }; string s = new string(chars, 0, chars.Length); // assign string from a char pointer, derived from a string string s; uns...

The ref and out keywords cause an argument to be passed by reference, not by value. For value types, this means that the value of the variable can be changed by the callee. int x = 5; ChangeX(ref x); // The value of x could be different now For reference types, the instance in the variable can...

List<int> l2 = l1.FindAll(x => x > 6); Here x => x > 6 is a lambda expression acting as a predicate that makes sure that only elements above 6 are returned.

When you want to catch an exception and do something, but you can't continue execution of the current block of code because of the exception, you may want to rethrow the exception to the next exception handler in the call stack. There are good ways and bad ways to do this. private static void AskTh...

public class Model { public string Name { get; set; } public bool? Selected { get; set; } } Here we have a Class with no constructor with two properties: Name and a nullable boolean property Selected. If we wanted to initialize a List<Model>, there are a few different ways to ex...

public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = x => x * 2; The above Lambda expression syntax is equivalent to the following verbose code: public delegate int ModifyInt(int input); ModifyInt multiplyByTwo = delegate(int x){ return x * 2; };

class Program { static void Main(string[] args) { // Create 2 thread objects. We're using delegates because we need to pass // parameters to the threads. var thread1 = new Thread(new ThreadStart(() => PerformAction(1))); var thread2 = new Thread(...

var letters = "letters".ToCharArray(); char letter = letters[1]; Console.WriteLine("Second Letter is {0}",letter); //in the above example we take the second character from the array //by calling letters[1] //NB: Array Indexing starts at 0; i.e. the first letter would be give...

using System.Text; //allows you to access classes within this namespace such as StringBuilder //without prefixing them with the namespace. i.e: //... var sb = new StringBuilder(); //instead of var sb = new System.Text.StringBuilder();

Notes: This example must be run in administrative mode. Only one simultaneous client is supported. For simplicity, filenames are assumed to be all ASCII (for the filename part in the Content-Disposition header) and file access errors are not handled. using System; using System.IO; using Syst...

The ConfigurationManager class supports the AppSettings property, which allows you to continue reading settings from the appSettings section of a configuration file the same way as .NET 1.x supported. app.config <?xml version="1.0" encoding="utf-8"?> <configuration&gt...

Starting from a new Settings class and custom configuration section: Add an application setting named ExampleTimeout, using the time System.Timespan, and set the value to 1 minute: Save the Project Properties, which saves the Settings tab entries, as well as re-generates the custom Settings cl...

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...

When we talk about the GC and the "heap", we're really talking about what's called the managed heap. Objects on the managed heap can access resources not on the managed heap, for example, when writing to or reading from a file. Unexpected behavior can occur when, a file is opened for readi...

A method can return either nothing (void), or a value of a specified type: // If you don't want to return a value, use void as return type. static void ReturnsNothing() { Console.WriteLine("Returns nothing"); } // If you want to return a value, you need to specify its type. st...

public IEnumerable<User> SelectUsers() { // Execute an SQL query on a database. using (IDataReader reader = this.Database.ExecuteReader(CommandType.Text, "SELECT Id, Name FROM Users")) { while (reader.Read()) { int id = reader.GetInt32(0...

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...

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...