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o
o
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o
o

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o
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o

var entry = new { Dim entry = New With { _
Title = "Dear Diary", .Title = "Dear Diary", _
DateTime.Now DateTime.Now _
}; }
Console.WriteLine("{0:d}: {1}", Console.WriteLine("{0:d}: {1}", _
entry.Now, entry.Title); entry.Now, entry.Title)
var Dim

 static Module
 using Imports

Imports System.Runtime.CompilerServices
Module StringExtensions
<Extension()> _
Public Sub Print(ByVal aString As String)
Console.WriteLine(aString)
End Sub
End Module
Dim hello = "Hello from StringExtensions"
hello.Print()

 this
static void ForEach<T>(this IEnumerable<T> source, Action<T> action)
{
foreach (T o in source)
action(o);
}

delegate void Action();
delegate void Action<T>(T arg);
delegate void Action<T1, T2>(T1 arg1, T2 arg2);
delegate TResult Func<TResult>();
delegate TResult Func<T, TResult>(T arg);
delegate TResult Func<T1, T2, TResult>(T1 arg1, T2 arg2);


delegate string MyDelegate(int i);
static string MyMethod(int i) { … }
MyDelegate del1 = new MyDelegate(MyMethod); // C# 1.0
MyDelegate del2 = delegate(int i) { … }; // C# 2.0
MyDelegate del3 = MyMethod; // C# 2.0
MyDelegate del4 = (int i) => { … }; // C# 3.0
Func<int, string> del5 = i => { … }; // C# 3.0

Dim del4 As MyDelegate = Function(i As Integer) …




Expression<Func<int, int>> inc = (a => a + 1);

ParameterExpression CS$a;
Expression<Func<int, int>> inc =
Expression.Lambda<Func<int, int>>(
Expression.Add(
CS$a = Expression.Parameter(typeof(int), "a"),
Expression.Constant(1, typeof(int))),
new ParameterExpression[] { CS$a });


var names = from s in Students
where s.Age % 2 == 0
orderby s.Name descending
select s.Name;

IEnumerable<string> names =
Students.Where(s => s.Age % 2 == 0)
.OrderByDescending(s => s.Name)
.Select(s => s.Name);


o
o

o
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o


o 
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o 
o 
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o 
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o
o 
o 
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o 
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o 
o 

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


from x1 in e1
join x2 in e2 on k1 equals k2
…

from * in ( e1 ) . Join(
e2 , x1 => k1 , x2 => k2 , (x1 , x2) => new { x1 , x2 })
…

o this
o
o
o
o


o EqualityComparer<TKey>.Default

o Equals() GetHashcode()
o
 IEqualityComparer<TKey>
o
o

 into
o
o Func<TOuter, TInner, TResult> resultSelector
 into
o
o
o Func<TOuter, IEnumerable<TInner>, TResult> resultSelector

o DefaultIfEmpty()
from x1 in e1
join x2 in e2 on k1 equals k2 into j
from xj in j . DefaultIfEmpty()
…

 from
o IEnumerable<T>

from x1 in e1
from x2 in e2
…

from * in ( e1 ) . SelectMany(
x1 => e2 , ( x1 , x2 ) => new { x1 , x2 } )
…
 *
o



o IEnumerable<T>

o yield return

o
o
o
o

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o
o
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o
• foreach
o
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o
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o


o
o IEnumerable<>

o
o EnumerableRowCollection<DataRow>
AsEnumerable(this DataTable source)
o EnumerableRowCollectionExtensions

o Cast<T>() OfType<T>()
o foreach
from MyType obj in MyArrayList
…



o IQueryable<T>
public interface IQueryable : IEnumerable
{
Type ElementType { get; }
Expression Expression { get; }
IQueryProvider Provider { get; }
}
public interface IQueryable<T> :
IEnumerable<T>, IQueryable, IEnumerable
{ }


public interface IQueryProvider
{
IQueryable CreateQuery(Expression expression);
IQueryable<TElement>
CreateQuery<TElement>(Expression expression);
object Execute(Expression expression);
TResult Execute<TResult>(Expression expression);
}

public static TSource First<TSource>(
this IQueryable<TSource> source)
{
return source.Provider.Execute<TSource>(
Expression.Call(null,
((MethodInfo) MethodBase.GetCurrentMethod())
.MakeGenericMethod(new Type[] { typeof(TSource) }),
new Expression[] { source.Expression }
)
);
}

 IEnumerable IQueryable

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o
o
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o
o

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o
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o
o
o