Tutorial by Examples: l

var numbers = new[] {1,2,3,4,5}; var sameNumbers = new[] {1,2,3,4,5}; var sameNumbersInDifferentOrder = new[] {5,1,4,2,3}; var equalIfSameOrder = numbers.SequenceEqual(sameNumbers); Console.WriteLine(equalIfSameOrder); //True var equalIfDifferentOrder = numbers.SequenceEqual(sameNumbersInDi...

var numbers = new[] {1,2,3,4,5,6,7,8,9,10}; var someNumbers = numbers.Where(n => n < 6); Console.WriteLine(someNumbers.GetType().Name); //WhereArrayIterator`1 var someNumbersList = someNumbers.ToList(); Console.WriteLine( someNumbersList.GetType().Name + " - " + ...

var names = new[] {"Foo","Bar","Fizz","Buzz"}; var thirdName = names.ElementAt(2); Console.WriteLine(thirdName); //Fizz //The following throws ArgumentOutOfRangeException var minusOnethName = names.ElementAt(-1); var fifthName = names.ElementAt(4); ...

var names = new[] {"Foo","Bar","Fizz","Buzz"}; var thirdName = names.ElementAtOrDefault(2); Console.WriteLine(thirdName); //Fizz var minusOnethName = names.ElementAtOrDefault(-1); Console.WriteLine(minusOnethName); //null var fifthName = names.Eleme...

var numbers = new[] {2,4,6,8,1,3,5,7}; var oddNumbers = numbers.SkipWhile(n => (n & 1) == 0); Console.WriteLine(string.Join(",", oddNumbers.ToArray())); //1,3,5,7

var numbers = new[] {2,4,6,1,3,5,7,8}; var evenNumbers = numbers.TakeWhile(n => (n & 1) == 0); Console.WriteLine(string.Join(",", evenNumbers.ToArray())); //2,4,6

var numbers = new[] {2,4,6,8,1,3,5,7}; var numbersOrDefault = numbers.DefaultIfEmpty(); Console.WriteLine(numbers.SequenceEqual(numbersOrDefault)); //True var noNumbers = new int[0]; var noNumbersOrDefault = noNumbers.DefaultIfEmpty(); Console.WriteLine(noNumbersOrDefault.Count()); //1 C...

Generating a new object in each step: var elements = new[] {1,2,3,4,5}; var commaSeparatedElements = elements.Aggregate( seed: "", func: (aggregate, element) => $"{aggregate}{element},"); Console.WriteLine(commaSeparatedElements); //1,2,3,4,5, Using th...

var persons = new[] { new { Name="Fizz", Job="Developer"}, new { Name="Buzz", Job="Developer"}, new { Name="Foo", Job="Astronaut"}, new { Name="Bar", Job="Astronaut"}, }; var groupedByJob = person...

public interface IAnimal { string Name { get; set; } } public interface INoiseMaker { string MakeNoise(); } public class Cat : IAnimal, INoiseMaker { public Cat() { Name = "Cat"; } public string Name { get; set; } public string M...

public class LivingBeing { string Name { get; set; } } public interface IAnimal { bool HasHair { get; set; } } public interface INoiseMaker { string MakeNoise(); } //Note that in C#, the base class name must come before the interface names public class Cat : LivingBei...

try, catch, finally, and throw allow you to handle exceptions in your code. var processor = new InputProcessor(); // The code within the try block will be executed. If an exception occurs during execution of // this code, execution will pass to the catch block corresponding to the exception typ...

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(); ...

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...