3. THANK YOU TO OUR
TEAM
ANDRÉ BATISTA ANDRÉ MELANCIA ANDRÉ VALA ANTÓNIO LOURENÇO BRUNO LOPES CLÁUDIO SILVA
NIKO NEUGEBAUER
RUI REISRICARDO CABRAL
NUNO CANCELO PAULO MATOS PEDRO SIMÕES
SANDRA MORGADO SANDRO PEREIRARUI BASTOS
NUNO ÁRIAS SILVA
6. Agenda
• Improvements in Auto-Properties
• Expression Bodied Function Members
• The 'using static' Directive
• Null-Conditional Operator
• String Interpolation
• 'nameof' Expressions
• 'Add' Extension Methods in Collection Initializers
• Index Initializers
• Exception Filters
• 'await' in 'catch' and 'finally' blocks
• C# Interactive
7. Improvements in Auto-Properties
Initializers for Auto-Properties
public class Person
{
private string firstName = "Jane"
private string lastName = "Doe";
public string FirstName
{
get { return firstName; }
set { firstName = value; }
}
public string LastName
{
get { return lastName; }
set { lastName = value; }
}
}
8. Improvements in Auto-Properties
Initializers for Auto-Properties
public class Person
{
public string FirstName { get; set; } = "Jane";
public string LastName { get; set; } = "Doe";
}
C# 6
9. Improvements in Auto-Properties
Read-Only Auto-Properties
public class Person
{
private readonly string firstName = "Jane";
private readonly string lastName = "Doe";
public string FirstName
{
get { return firstName; }
}
public string LastName
{
get { return lastName; }
}
// ...
public Person(string first, string last)
{
firstName = first;
lastName = last;
}
}
10. Improvements in Auto-Properties
Read-Only Auto-Properties
public class Person
{
public string FirstName { get; } = "Jane";
public string LastName { get; } = "Doe";
// ...
public Person(string first, string last)
{
FirstName = first;
LastName = last;
}
}
C# 6
11. Expression Bodied Function Members
Expression Bodied Method-Like Function Members
public Point Move(int dx, int dy)
{
return new Point(x + dx, y + dy);
}
public static Complex operator +(Complex a, Complex b)
{
return a.Add(b);
}
public static implicit operator string(Person p)
{
return p.First + " " + p.Last;
}
12. Expression Bodied Function Members
Expression Bodied Method-Like Function Members
public Point Move(int dx, int dy) =>
new Point(x + dx, y + dy);
public static Complex operator +(Complex a, Complex b) =>
a.Add(b);
public static implicit operator string (Person p) =>
p.First + " " + p.Last;
C# 6
13. Expression Bodied Function Members
Expression Bodied Property-Like Function Members
public string Name
{
get { return First + " " + Last; }
}
public Person this[long id]
{
get { return store.LookupPerson(id); }
}
14. Expression Bodied Function Members
Expression Bodied Property-Like Function Members
public string Name => First + " " + Last;
public Person this[long id] => store.LookupPerson(id);
C# 6
15. The 'using static' Directive
using System;
class Program
{
static void Main()
{
Console.WriteLine(Math.Sqrt(3 * 3 + 4 * 4));
Console.WriteLine(DayOfWeek.Friday - DayOfWeek.Monday);
}
}
16. The 'using static' Directive
using static System.Console;
using static System.Math;
using static System.DayOfWeek;
class Program
{
static void Main()
{
WriteLine(Sqrt(3 * 3 + 4 * 4));
WriteLine(Friday - Monday);
}
}
C# 6
17. The 'using static' Directive
Extension Methods
using static System.Linq.Enumerable; // The type, not the namespace
class Program
{
static void Main()
{
var range = Range(5, 17); // Ok: not extension
var odd = Where(range, i => i % 2 == 1); // Error, not in scope
var even = range.Where(i => i % 2 == 0); // Ok
}
}
C# 6
18. Null-Conditional Operator
Property and Method Invocation
int? nullable = (people != null) ? new int?(people.Length) : null;
Person first = (people != null) ? people[0] : null;
int? firstCount = (people != null) ? people[0].Orders.Count() : (int?)null;
int firstCount = (people != null) ? people[0].Orders.Count() : 0;
19. Null-Conditional Operator
Property and Method Invocation
int? length = people?.Length; // null if people is null
Person first = people?[0]; // null if people is null
int length = people?.Length ?? 0; // 0 if people is null
int? firstCount = people?[0].Orders.Count();
C# 6
25. String Interpolation
Formattable Strings
FormattableStringFactory.Create("{0:f}", new DateTime(2015, 12, 25))
public abstract class FormattableString : IFormattable
{
protected FormattableString();
public abstract int ArgumentCount { get; }
public abstract string Format { get; }
public static string Invariant(FormattableString formattable);
public abstract object GetArgument(int index);
public abstract object[] GetArguments();
public override string ToString();
public abstract string ToString(IFormatProvider formatProvider);
}
C# 6
29. 'nameof' Expressions
void M1(string x)
{
if (x == null) throw new ArgumentNullException(nameof(x));
var s = nameof(Person.Address.ZipCode);
}
C# 6
30. 'nameof' Expressions
Source Code vs. Metadata
using S = System.String;
void M<T>(S s)
{
var s1 = nameof(T);
var s2 = nameof(S);
}
using S = System.String;
void M<T>(S s)
{
var s1 = "T";
var s2 = "S";
}
C# 6
31. Collection Initializers
'Add' Extension Methods
public class C<T> : IEnumerable<T>
{
// ...
}
public static class Cx
{
public static void Add<T>(this C<T> c, T i)
{
// ...
}
}
var cs = new C<int>();
cs.Add(1);
cs.Add(2);
cs.Add(3);
32. Collection Initializers
'Add' Extension Methods
public class C<T> : IEnumerable<T>
{
// ...
}
public static class Cx
{
public static void Add<T>(this C<T> c, T i)
{
// ...
}
}
var cs = new C<int> { 1, 2, 3 };
C# 6
33. Index Initializers
var numbers = new Dictionary<int, string>();
numbers[7] = "seven";
numbers[9] = "nine";
numbers[13] = "thirteen";