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Overloading just equality operators is not enough. Under different circumstances, all of the following can be called: object.Equals and object.GetHashCode IEquatable<T>.Equals (optional, allows avoiding boxing) operator == and operator != (optional, allows using operators) When overrid...

To make a class support collection initializers, it must implement IEnumerable interface and have at least one Add method. Since C# 6, any collection implementing IEnumerable can be extended with custom Add methods using extension methods. class Program { static void Main() { va...

Extension methods are static methods which behave like instance methods. However, unlike what happens when calling an instance method on a null reference, when an extension method is called with a null reference, it does not throw a NullReferenceException. This can be quite useful in some scenarios....

Apostrophes char apostrophe = '\''; Backslash char oneBackslash = '\\';

Backslash // The filename will be c:\myfile.txt in both cases string filename = "c:\\myfile.txt"; string filename = @"c:\myfile.txt"; The second example uses a verbatim string literal, which doesn't treat the backslash as an escape character. Quotes string text = "\&...

try { /* code that could throw an exception */ } catch (Exception ex) { /* handle the exception */ } Note that handling all exceptions with the same code is often not the best approach. This is commonly used when any inner exception handling routines fail, as a last resort.

try { /* code to open a file */ } catch (System.IO.FileNotFoundException) { /* code to handle the file being not found */ } catch (System.IO.UnauthorizedAccessException) { /* code to handle not being allowed access to the file */ } catch (System.IO.IOException) { /* cod...

You are allowed to create and throw exceptions in your own code. Instantiating an exception is done the same way that any other C# object. Exception ex = new Exception(); // constructor with an overload that takes a message string Exception ex = new Exception("Error message"); Yo...

try { /* code that could throw an exception */ } catch (Exception) { /* handle the exception */ } finally { /* Code that will be executed, regardless if an exception was thrown / caught or not */ } The try / catch / finally block can be very handy when reading from files. ...

Similarly to the ?. operator, the null-conditional index operator checks for null values when indexing into a collection that may be null. string item = collection?[index]; is syntactic sugar for string item = null; if(collection != null) { item = collection[index]; }

// 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...

// assigning a signed short to its minimum value short s = -32768; // assigning a signed short to its maximum value short s = 32767; // assigning a signed int to its minimum value int i = -2147483648; // assigning a signed int to its maximum value int i = 2147483647; // assigning a s...

// assigning an unsigned short to its minimum value ushort s = 0; // assigning an unsigned short to its maximum value ushort s = 65535; // assigning an unsigned int to its minimum value uint i = 0; // assigning an unsigned int to its maximum value uint i = 4294967295; // assigning an...

In order to be able to manage your projects' packages, you need the NuGet Package Manager. This is a Visual Studio Extension, explained in the official docs: Installing and Updating NuGet Client. Starting with Visual Studio 2012, NuGet is included in every edition, and can be used from: Tools ->...

When you right-click a project (or its References folder), you can click the "Manage NuGet Packages..." option. This shows the Package Manager Dialog.

Click the menus Tools -> NuGet Package Manager -> Package Manager Console to show the console in your IDE. Official documentation here. Here you can issue, amongst others, install-package commands which installs the entered package into the currently selected "Default project": Ins...

public class SomeClass { public void DoStuff() { } protected void DoMagic() { } } public static class SomeClassExtensions { public static void DoStuffWrapper(this SomeClass someInstance) { someInstance.DoStuff(); // ok ...

You can enumerate through a Dictionary in one of 3 ways: Using KeyValue pairs Dictionary<int, string> dict = new Dictionary<int, string>(); foreach(KeyValuePair<int, string> kvp in dict) { Console.WriteLine("Key : " + kvp.Key.ToString() + ", Value : " +...

// Translates to `dict.Add(1, "First")` etc. var dict = new Dictionary<int, string>() { { 1, "First" }, { 2, "Second" }, { 3, "Third" } }; // Translates to `dict[1] = "First"` etc. // Works in C# 6.0. var dict = new Dicti...

Dictionary<int, string> dict = new Dictionary<int, string>(); dict.Add(1, "First"); dict.Add(2, "Second"); // To safely add items (check to ensure item does not already exist - would throw) if(!dict.ContainsKey(3)) { dict.Add(3, "Third"); } Al...