var numbers1to5 = new[] {1, 2, 3, 4, 5};
var numbers4to8 = new[] {4, 5, 6, 7, 8};
var numbers1to8 = numbers1to5.Concat(numbers4to8);
Console.WriteLine(string.Join(",", numbers1to8));
//1,2,3,4,5,4,5,6,7,8
Note that duplicates are kept in the result. If this is undesirable, use...
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 oneNumber = new[] {5};
var theOnlyNumber = oneNumber.Single();
Console.WriteLine(theOnlyNumber); //5
var numbers = new[] {1,2,3,4,5};
var theOnlyNumberSmallerThanTwo = numbers.Single(n => n < 2);
Console.WriteLine(theOnlyNumberSmallerThanTwo); //1
The following throws Invalid...
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...
Returns true if the collection has any elements that meets the condition in the lambda expression:
var numbers = new[] {1,2,3,4,5};
var isNotEmpty = numbers.Any();
Console.WriteLine(isNotEmpty); //True
var anyNumberIsOne = numbers.Any(n => n == 1);
Console.WriteLine(anyNumberIsOne); //Tr...
The readonly keyword is a field modifier. When a field declaration includes a readonly modifier, assignments to that field can only occur as part of the declaration or in a constructor in the same class.
The readonly keyword is different from the const keyword. A const field can only be initialized...
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 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...
Returns a new dictionary from the source IEnumerable using the provided keySelector function to determine keys. Will throw an ArgumentException if keySelector is not injective(returns a unique value for each member of the source collection.) There are overloads which allow one to specify the value t...
var numbers1to5 = new[] {1,2,3,4,5};
var numbers4to8 = new[] {4,5,6,7,8};
var numbers1to8 = numbers1to5.Union(numbers4to8);
Console.WriteLine(string.Join(",", numbers1to8));
//1,2,3,4,5,6,7,8
Note that duplicates are removed from the result. If this is undesirable, use Concat ...
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);
...
class Developer
{
public int Id { get; set; }
public string Name { get; set; }
}
class Project
{
public int DeveloperId { get; set; }
public string Name { get; set; }
}
var developers = new[] {
new Developer {
Id = 1,
Name = "Foobuzz"
...
class Developer
{
public int Id { get; set; }
public string Name { get; set; }
}
class Project
{
public int DeveloperId { get; set; }
public string Name { get; set; }
}
var developers = new[] {
new Developer {
Id = 1,
Name = "Foobuzz"
...
const is used to represent values that will never change throughout the lifetime of the program. Its value is constant from compile-time, as opposed to the readonly keyword, whose value is constant from run-time.
For example, since the speed of light will never change, we can store it in a constan...
The namespace keyword is an organization construct that helps us understand how a codebase is arranged. Namespaces in C# are virtual spaces rather than being in a physical folder.
namespace StackOverflow
{
namespace Documentation
{
namespace CSharp.Keywords
{
...
