Enumerable.Any Methode
Definition
Bestimmt, ob ein Element einer Sequenz vorhanden ist oder eine Bedingung erfülltDetermines whether any element of a sequence exists or satisfies a condition.
Überlädt
Any<TSource>(IEnumerable<TSource>) |
Bestimmt, ob eine Sequenz Elemente enthält.Determines whether a sequence contains any elements. |
Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) |
Bestimmt, ob ein Element einer Sequenz eine Bedingung erfüllt.Determines whether any element of a sequence satisfies a condition. |
Any<TSource>(IEnumerable<TSource>)
Bestimmt, ob eine Sequenz Elemente enthält.Determines whether a sequence contains any elements.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static bool Any(System::Collections::Generic::IEnumerable<TSource> ^ source);
public static bool Any<TSource> (this System.Collections.Generic.IEnumerable<TSource> source);
static member Any : seq<'Source> -> bool
<Extension()>
Public Function Any(Of TSource) (source As IEnumerable(Of TSource)) As Boolean
Typparameter
- TSource
Der Typ der Elemente von source
.The type of the elements of source
.
Parameter
- source
- IEnumerable<TSource>
Das IEnumerable<T>, bei dem überprüft werden soll, ob es leer ist.The IEnumerable<T> to check for emptiness.
Gibt zurück
true
, wenn die Quellsequenz Elemente enthält, andernfalls false
.true
if the source sequence contains any elements; otherwise, false
.
Ausnahmen
source
ist null
.source
is null
.
Beispiele
Im folgenden Codebeispiel wird veranschaulicht, wie verwendet wird, Any um zu bestimmen, ob eine Sequenz Elemente enthält.The following code example demonstrates how to use Any to determine whether a sequence contains any elements.
List<int> numbers = new List<int> { 1, 2 };
bool hasElements = numbers.Any();
Console.WriteLine("The list {0} empty.",
hasElements ? "is not" : "is");
// This code produces the following output:
//
// The list is not empty.
' Create a list of Integers.
Dim numbers As New List(Of Integer)(New Integer() {1, 2})
' Determine if the list contains any items.
Dim hasElements As Boolean = numbers.Any()
' Display the output.
Dim text As String = IIf(hasElements, "not ", "")
Console.WriteLine($"The list is {text}empty.")
' This code produces the following output:
'
' The list is not empty.
Der boolesche Wert, der Any<TSource>(IEnumerable<TSource>) von der-Methode zurückgegeben wird, wird in der Regel im Prädikat einer- where
Klausel (- Where
Klausel in Visual Basic) oder einem direkten Aufrufder- Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) Methode verwendet.The Boolean value that the Any<TSource>(IEnumerable<TSource>) method returns is typically used in the predicate of a where
clause (Where
clause in Visual Basic) or a direct call to the Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) method. Im folgenden Beispiel wird die Verwendung der- Any
Methode veranschaulicht.The following example demonstrates this use of the Any
method.
class Pet
{
public string Name { get; set; }
public int Age { get; set; }
}
class Person
{
public string LastName { get; set; }
public Pet[] Pets { get; set; }
}
public static void AnyEx2()
{
List<Person> people = new List<Person>
{ new Person { LastName = "Haas",
Pets = new Pet[] { new Pet { Name="Barley", Age=10 },
new Pet { Name="Boots", Age=14 },
new Pet { Name="Whiskers", Age=6 }}},
new Person { LastName = "Fakhouri",
Pets = new Pet[] { new Pet { Name = "Snowball", Age = 1}}},
new Person { LastName = "Antebi",
Pets = new Pet[] { }},
new Person { LastName = "Philips",
Pets = new Pet[] { new Pet { Name = "Sweetie", Age = 2},
new Pet { Name = "Rover", Age = 13}} }
};
// Determine which people have a non-empty Pet array.
IEnumerable<string> names = from person in people
where person.Pets.Any()
select person.LastName;
foreach (string name in names)
{
Console.WriteLine(name);
}
/* This code produces the following output:
Haas
Fakhouri
Philips
*/
}
Structure Pet
Public Name As String
Public Age As Integer
End Structure
Structure Person
Public LastName As String
Public Pets() As Pet
End Structure
Sub AnyEx2()
Dim people As New List(Of Person)(New Person() _
{New Person With {.LastName = "Haas",
.Pets = New Pet() {New Pet With {.Name = "Barley", .Age = 10},
New Pet With {.Name = "Boots", .Age = 14},
New Pet With {.Name = "Whiskers", .Age = 6}}},
New Person With {.LastName = "Fakhouri",
.Pets = New Pet() {New Pet With {.Name = "Snowball", .Age = 1}}},
New Person With {.LastName = "Antebi",
.Pets = New Pet() {}},
New Person With {.LastName = "Philips",
.Pets = New Pet() {New Pet With {.Name = "Sweetie", .Age = 2},
New Pet With {.Name = "Rover", .Age = 13}}}})
' Determine which people have a non-empty Pet array.
Dim names = From person In people
Where person.Pets.Any()
Select person.LastName
For Each name As String In names
Console.WriteLine(name)
Next
' This code produces the following output:
'
' Haas
' Fakhouri
' Philips
End Sub
Hinweise
Hinweis
Diese Methode gibt kein Element einer Auflistung zurück.This method does not return any one element of a collection. Stattdessen bestimmt er, ob die Auflistung Elemente enthält.Instead, it determines whether the collection contains any elements.
Die Enumeration von source
wird beendet, sobald das Ergebnis bestimmt werden kann.The enumeration of source
is stopped as soon as the result can be determined.
In Visual Basic Abfrage Ausdruckssyntax übersetzt eine- Aggregate Into Any()
Klausel in einen Aufruf von Any .In Visual Basic query expression syntax, an Aggregate Into Any()
clause translates to an invocation of Any.
Siehe auch
- Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)
- Aggregate-Klausel (Visual Basic)Aggregate Clause (Visual Basic)
Gilt für:
Any<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)
Bestimmt, ob ein Element einer Sequenz eine Bedingung erfüllt.Determines whether any element of a sequence satisfies a condition.
public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
static bool Any(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, bool> ^ predicate);
public static bool Any<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,bool> predicate);
static member Any : seq<'Source> * Func<'Source, bool> -> bool
<Extension()>
Public Function Any(Of TSource) (source As IEnumerable(Of TSource), predicate As Func(Of TSource, Boolean)) As Boolean
Typparameter
- TSource
Der Typ der Elemente von source
.The type of the elements of source
.
Parameter
- source
- IEnumerable<TSource>
Ein IEnumerable<T>, auf dessen Elemente das Prädikat angewendet werden soll.An IEnumerable<T> whose elements to apply the predicate to.
Eine Funktion, mit der jedes Element auf eine Bedingung überprüft wird.A function to test each element for a condition.
Gibt zurück
true
, wenn die Quellsequenz nicht leer ist und mindestens ein Element im angegebenen Prädikat erfolgreich überprüft wird; andernfalls false
.true
if the source sequence is not empty and at least one of its elements passes the test in the specified predicate; otherwise, false
.
Ausnahmen
source
oder predicate
ist null
.source
or predicate
is null
.
Beispiele
Im folgenden Codebeispiel wird veranschaulicht, wie verwendet wird, Any um zu bestimmen, ob ein beliebiges Element in einer Sequenz eine Bedingung erfüllt.The following code example demonstrates how to use Any to determine whether any element in a sequence satisfies a condition.
class Pet
{
public string Name { get; set; }
public int Age { get; set; }
public bool Vaccinated { get; set; }
}
public static void AnyEx3()
{
// Create an array of Pets.
Pet[] pets =
{ new Pet { Name="Barley", Age=8, Vaccinated=true },
new Pet { Name="Boots", Age=4, Vaccinated=false },
new Pet { Name="Whiskers", Age=1, Vaccinated=false } };
// Determine whether any pets over age 1 are also unvaccinated.
bool unvaccinated =
pets.Any(p => p.Age > 1 && p.Vaccinated == false);
Console.WriteLine(
"There {0} unvaccinated animals over age one.",
unvaccinated ? "are" : "are not any");
}
// This code produces the following output:
//
// There are unvaccinated animals over age one.
Structure Pet
Public Name As String
Public Age As Integer
Public Vaccinated As Boolean
End Structure
Shared Sub AnyEx3()
' Create a list of Pets
Dim pets As New List(Of Pet)(New Pet() _
{New Pet With {.Name = "Barley", .Age = 8, .Vaccinated = True},
New Pet With {.Name = "Boots", .Age = 4, .Vaccinated = False},
New Pet With {.Name = "Whiskers", .Age = 1, .Vaccinated = False}})
' Determine whether any pets over age 1 are also unvaccinated.
Dim unvaccinated As Boolean =
pets.Any(Function(pet) pet.Age > 1 And pet.Vaccinated = False)
' Display the output.
Dim text As String = IIf(unvaccinated, "are", "are not")
Console.WriteLine($"There {text} unvaccinated animals over age 1.")
End Sub
' This code produces the following output:
'
' There are unvaccinated animals over age 1.
Hinweise
Hinweis
Diese Methode gibt kein Element einer Auflistung zurück.This method does not return any one element of a collection. Stattdessen bestimmt Sie, ob Elemente einer Auflistung eine Bedingung erfüllen.Instead, it determines whether any elements of a collection satisfy a condition.
Die Enumeration von source
wird beendet, sobald das Ergebnis bestimmt werden kann.The enumeration of source
is stopped as soon as the result can be determined.
In Visual Basic Abfrage Ausdruckssyntax übersetzt eine- Aggregate Into Any()
Klausel in einen Aufruf von Any .In Visual Basic query expression syntax, an Aggregate Into Any()
clause translates to an invocation of Any.