Tutorial by Examples: f

Returns an int holding the size of a type* in bytes. sizeof(bool) // Returns 1. sizeof(byte) // Returns 1. sizeof(sbyte) // Returns 1. sizeof(char) // Returns 2. sizeof(short) // Returns 2. sizeof(ushort) // Returns 2. sizeof(int) // Returns 4. sizeof(uint) // Returns 4....

public class Dog { private const string _birthStringFormat = "yyyy-MM-dd"; [XmlIgnore] public DateTime Birth {get; set;} [XmlElement(ElementName="Birth")] public string BirthString { get { return Birth.ToString(_birthStringFormat); } ...

The finally { ... } block of a try-finally or try-catch-finally will always execute, regardless of whether an exception occurred or not (except when a StackOverflowException has been thrown or call has been made to Environment.FailFast()). It can be utilized to free or clean up resources acquired i...

This method returns an IEnumerable with all the elements that meets the lambda expression Example var personNames = new[] { "Foo", "Bar", "Fizz", "Buzz" }; var namesStartingWithF = personNames.Where(p => p.StartsWith("F")); Console.W...

var numbers = new[] {1,2,3,4,5}; var firstNumber = numbers.First(); Console.WriteLine(firstNumber); //1 var firstEvenNumber = numbers.First(n => (n & 1) == 0); Console.WriteLine(firstEvenNumber); //2 The following throws InvalidOperationException with message "Sequence contain...

var numbers = new[] {1,2,3,4,5}; var lastNumber = numbers.LastOrDefault(); Console.WriteLine(lastNumber); //5 var lastEvenNumber = numbers.LastOrDefault(n => (n & 1) == 0); Console.WriteLine(lastEvenNumber); //4 var lastNegativeNumber = numbers.LastOrDefault(n => n < 0); Con...

var oneNumber = new[] {5}; var theOnlyNumber = oneNumber.SingleOrDefault(); Console.WriteLine(theOnlyNumber); //5 var numbers = new[] {1,2,3,4,5}; var theOnlyNumberSmallerThanTwo = numbers.SingleOrDefault(n => n < 2); Console.WriteLine(theOnlyNumberSmallerThanTwo); //1 var theOnl...

var numbers = new[] {1,2,3,4,5}; var firstNumber = numbers.FirstOrDefault(); Console.WriteLine(firstNumber); //1 var firstEvenNumber = numbers.FirstOrDefault(n => (n & 1) == 0); Console.WriteLine(firstEvenNumber); //2 var firstNegativeNumber = numbers.FirstOrDefault(n => n < ...

For classes, interfaces, delegate, array, nullable (such as int?) and pointer types, default(TheType) returns null: class MyClass {} Debug.Assert(default(MyClass) == null); Debug.Assert(default(string) == null); For structs and enums, default(TheType) returns the same as new TheType(): struct...

Enumerable.Select returns an output element for every input element. Whereas Enumerable.SelectMany produces a variable number of output elements for each input element. This means that the output sequence may contain more or fewer elements than were in the input sequence. Lambda expressions passe...

var mixed = new object[] {1,"Foo",2,"Bar",3,"Fizz",4,"Buzz"}; var numbers = mixed.OfType<int>(); Console.WriteLine(string.Join(",", numbers.ToArray())); //1,2,3,4

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 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...

Returns the Type of an object, without the need to instantiate it. Type type = typeof(string); Console.WriteLine(type.FullName); //System.String Console.WriteLine("Hello".GetType() == type); //True Console.WriteLine("Hello".GetType() == typeof(string)); //True

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...

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...

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. ...