C# has evolved over several versions to include many new features such as generics, lambda expressions, extension methods, dynamic binding, and more. C# 6 added features like using statements for static members and auto-property initializers. C# 7 included tuples, pattern matching, and local functions. C# 8 focuses on record types, default interface methods, nullable reference types, null coalescing assignment, recursive patterns, negated-condition if statements, and null-conditional await.

1. The State of C#
What Have I Missed?
Filip Ekberg

2. Microsoft MVP
@fekberg
Filip Ekberg

3. The Best of All Worlds – C#

4. C# 2.0
Generics
Partial types
Anonymous methods
Iterators
Nullable types
Getter/Setter separate accessibility
Static classes
And more..
Implicitly typed local variables
Object and collection initializers
Auto-properties
Anonymous types
Extension methods
Query expressions
Lambda expressions
Expression trees
And more..
Dynamic binding
Named and optional parameters
Generic co- and contravariance
And more..
C# 3.0 C# 4.0
Asynchronous methods
Caller info attributes
C# 5.0

9. No more
Language Parity

10. C# 6.0
Using Statements for Static Members
Auto-Property Initializers
Await inside Catch & Finally blocks
Null-conditional operators
String interpolation
Dictionary Initializers
Expression-bodied members
Exception Filters
nameof operator

11. C# 7.0
Tuples and Deconstruction
Pattern Matching
Digit Separator & Binary Literals
Local Functions
ref returns
out improvements

12. C# 8?

14. C# 7.1
Async Main
Default Expressions
Infer Tuple Names
Pattern-matching with Generics
Ref Assemblies

15. C# 7.2
ref readonly
public ref readonly T RefAt(int i)
Vector3 Add (in Vector3 v1, in Vector3 v2)
non-trailing named arguments
DoSomething(isEmployed:true, name, age);
private protected
CLR protectedAndInternal = private protected
conditional ref operator
<condition> ? ref <consequence> : ref <alternative>
digit separator after base specifier
0x_1_2

17. C# 8.0
Record Types
Default interface methods
Nullable reference type
Null coalescing assignment
Recursive patterns (+ Pattern Matching Improvements)
Negated-condition if statement
Null-conditional await
And More!!

18. Null Reference Exceptions

19. C#Record Types
public class Triangle : Shape
{
public int A { get; set; }
public int B { get; set; }
public int C { get; set; }
}
public class Triangle(int A, int B, int C )
: Shape {}

20. C#Default interface methods
interface IPoint
{
(int x, int y) GetPoint() { return (0, 0); }
}
class Point : IPoint
{ }
IPoint point = new Point();
point.GetPoint();

21. C#Nullable reference type
Point? point = new Point();
Point? point = null; // Boom?!

22. C#Null coalescing assignment
x = x ?? y
if(x == null) x = y;
x ??= y

23. C#Negated-condition if statement
if( !(shape is Triangle)) {};
if(shape is not Triangle) {};
if!(shape is Triangle) {};
unless (shape is Triangle) {};

24. C#Null-conditional await
(task == null) ? null : await task
await! task

25. Wrap Up

26. I’m Filip Ekberg
@fekberg
Thanks!