C# 6.0 and 7.0 new 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.