Slides de la charla de C# 6 / 7 new features impartida en MadridDotNet. Video de la charla: https://www.youtube.com/watch?v=RdgdU2x7lQ0 Enlace de la charla: https://www.meetup.com/madriddotnet/events/240450200/ Descripción de la charla: En esta charla repasaremos las features que el equipo de C# incluyo en la versión 6.0 y abordaremos las nuevas features de C# 7.0 escribiendo código en vivo para comprender estas nuevas características del lenguaje. C# 6.0 Features Null-Conditional Operator Null Coalescing Operator Auto-Property Initializers Using static Nameof Expressions Exception filters Await in catch and finally blocks Expression Bodied Functions and Properties String interpolation C# 7.0 Features Expresion bodied members Pattern Matching (Is) Pattern Matching (Switch) Local Functions Inline Out variables Returns by reference Throw expressions Tuples Deconstructions Async return types (ValueTask) BIO: Carlos Landeras Martínez Software Engineer en Plain Concepts Más de 9 años de experiencia en tecnologías .NET y desarrollo de aplicaciones Web. Apasionado de las nuevas arquitecturas y herramientas Front-End.

1. C#
6.0 & 7.0
Features

2. Carlos Landeras Martínez
Software Engineer at Plain Concepts
@carlos_lande
carlos.landeras@gmail.com
¿Who Am I?

3. A little bit of C# History

4. What’s What was new in C# 6.0
Read-only auto-properties
Auto-Property Initializers
Expression-bodied function members
Using Static
Null – Conditional Operators
String Interpolation
Exception filters
nameof Expressions
Await in catch and finally blocks
Index initializers

5. Read Only Auto Properties
Read-only auto-properties provide a more concise syntax to create immutable types, in previous C# Versions
the compiler only enforces properties not to be modified outside the class.
Read Only Auto Properties, enable true read-only behaviour, and true language support for immutable types
Note* : Read Only properties must be set inside the body of class constructor, trying to set them in other block
of code would end with a CS 0200 compilation error

6. Auto Property Initializers
Allows initialization of an Auto Property as part of the property declaration.

7. Expression bodied Function Members
The body of a lot of members that we write consist of only one statement that can be represented as an
expression

8. Using Static
The using static enhancement enables you to import the static methods of a single class.

9. Null Conditional Operator
Stop complicating your code by checking Null when accessing variables!. Yiiiiihaaaa!

10. String Interpolation
Welcome to the new Syntax for composing strings!

11. Exception filters
Determine when a given catch clause should be applied

12. Nameof Expression
The nameof expression evaluates to the name of a symbol

13. Await in catch and finally blocks
C# 6.0 allows to use await keyword y catch and finally blocks.

14. Index Initializers
Allow collection initialization to be more consistent. In earlier versions, we could use collection initializers
with sequence style collections, now we can even use them with Dictionaries.

15. What is new in C# 7.0
Expresion bodied members
Pattern Matching (Is)
Pattern Matching (Switch)
Local Functions
Inline Out variables
Returns by reference
Throw expressions
Tuples
Deconstructions
Async return types (ValueTask)

16. Expression bodied members
In C# 6.0 we had expression bodied function members, and this version has added accessors, constructors
and finalizers

17. Pattern Matching (is)
Syntactic elements that can test that a value has a certain “shape”, and extract information from the value
when it does.

18. Pattern Matching (Switch)
You can now switch on any type, not just primitive types.
Patterns can use case clauses, and this clauses can have additional conditions on them.

19. Local functions
If your helper function only makes sense inside the single method that is consuming it. You can now
declare it as a local function.

20. Inline out variables
Before C# 6.0, you had to declare variables you pass to out parameters, it is a little bit pointless since this
value will be overwritten. In C# 7.0 you can declare and use them inline.

21. Throw expressions
It is now possible to throw an exception in the middle of an expression ;)

22. Tuples and deconstructions
Tuples have arrived to C# 7.0!. You can stop creating dummy objects to return more than one value. The
options until now were:
• System.Tuple (Verbose and require allocation)
• Out parameters (Use is awkward, not working in async methods)
• Anonymous types through a dynamic. (overhead and no type checking)
Tuples are a new value type in C# language. This means Performance (no overhead like old Tuple, that
stored a class instance) and new software design capabilities.

23. Async return types
C# 7.0 introduces ValueTask. The main advantage of this new struct, it’s to prevent the Allocation of a new
Task<T> object in cases where the result of the async operation is already available at the time of awaiting.