C# is here to stay, it is time to embrace one of the most popular languages of the future and learn what is coming. In this talk we will look at how C# has evolved over time, and why it is definitely here to stay!

2. Author. Blogger. Speaker. .NET MVP. Xamarin MVP. Geek.
Senior Software Engineer @

10. class Program
{
static void Main(string[] args)
{
var angle = 90d;
Console.WriteLine(Math.Sin(angle));
}
}

11. using static System.Console;
using static System.Math;
class Program
{
static void Main(string[] args)
{
var angle = 90d;
WriteLine(Sin(angle));
}
}

12. using static System.Console;
using static System.Linq.Enumerable;
class Program
{
static void Main(string[] args)
{
foreach (var i in Range(0, 10))
{
WriteLine(i);
}
}
}

14. class Person
{
public string Name { get; set; }
}
class Person
{
public string Name { get; } = "Anonymous";
}

15. class Person
{
public string Name { get; }
public Person()
{
Name = "Filip";
}
}

16. class Person
{
private readonly string <Name>k__BackingField = "Filip";
public string Name
{
get
{
return this.<Name>k__BackingField;
}
}
}

18. public async Task DownloadAsync()
{
}
try
{ }
catch
{
await Task.Delay(2000);
}
finally
{
await Task.Delay(2000);
}

20. class Person
{
public string Name { get; set; }
public Address Address { get; set; }
}
Console.WriteLine(filip.Address == null ? "No Address" : filip.Address.AddressLine1);
Console.WriteLine(filip?.Address?.AddressLine1 ?? "No Address");
var filip = new Person
{
Name = "Filip"
};

21. var people = new[]
{
new Person(),
null
};
WriteLine(people[0]?.Name);
WriteLine(people[1]?.Name);

22. Person[] people = null;
WriteLine(people?[0]?.Name);
Person[] people = null;
Console.WriteLine(
(people != null) ?
((people[0] == null) ? null : people[0].Name)
: null
);

24. $"My Width is {Width} and my Height is {Height}";
string.Format("My Width is {0} and my Height is {1}", Width, Height);

25. int age = 28;
var result = $"Hello there, I'm {age:D5} years old!";
WriteLine(result);
int num = 28;
object[] objArray1 = new object[] { num };
Console.WriteLine(
string.Format("Hello there, I'm {0:D5} years old!", objArray1));

27. var people = new Dictionary<string, Person>
{
["Filip"] = new Person()
};
var answers = new Dictionary<int, string>
{
[42] = "the answer to life the universe and everything"
};

29. class Rectangle
{
public double Width { get; set; }
public double Height { get; set; }
public override string ToString() =>
$"My Width is {Width} and my Height is {Height}";
}

31. static void Main(string[] args)
{
WriteLine($"Parameter name is: {nameof(args)}");
}

33. try
{
throw new CustomException { Severity = 100 };
}
catch (CustomException ex) when (ex.Severity > 50)
{
Console.WriteLine("*BING BING* WARNING *BING BING*");
}
catch (CustomException ex)
{
Console.WriteLine("Whooops!");
}

34. C# 2.0
Generics
Partialtypes
Anonymousmethods
Iterators
Nullabletypes
Getter/Setterseparateaccessibility
Staticclasses
Andmore..
Implicitlytypedlocalvariables
Objectandcollectioninitializers
Auto-properties
Anonymoustypes
Extensionmethods
Queryexpressions
Lambdaexpressions
Expressiontrees
Andmore..
Dynamicbinding
Namedandoptionalparameters
Genericco-andcontravariance
Andmore..
C# 3.0
C# 4.0
Asynchronousmethods
Callerinfoattributes
C# 5.0

36. 0b00001000
0xFF_00_FA_AF
var client = new WebClient
{
DownloadFileCompleted += DownloadFileCompletedHandler
};
var y = (var x = Foo(); Write(x); x * x);[field: NonSerialized]
public int Age { get; set; }
Binary literals and Digit separators Event initializers
Field targets on auto-properties Semicolon operator

37. class Person(string name, int age)
{
private string _name = name;
private int _age = age;
}
public void CalculateAgeBasedOn(int birthYear, out int age)
{
age = DateTime.Now.Year - birthYear;
}
CalculateAgeBasedOn(1987, out var age);
int Avg(params IEnumerable<int> numbers)
Primary Constructors Using params with IEnumerable
Declaration Expressions

40. public (int sum, int count) Calculate(IEnumerable<int> numbers)
{
var total = numbers.Sum();
return (total, numbers.Count());
}
https://github.com/dotnet/roslyn/issues/1207
var result = Calculate(Enumerable.Range(0, 100));
WriteLine($"Total is {result.sum}, with {result.count} numbers.");

41. https://github.com/dotnet/roslyn/issues/206
public record class Point(int X, int Y);
if (expr is Point point)
{
// Use point here
}

43. https://github.com/dotnet/roslyn/issues/2136

48. Author. Blogger. Speaker. .NET MVP. Xamarin MVP. Geek.
Senior Software Engineer @