Enumerable.LongCount Method

Definition

Retorna um Int64 que representa o número de elementos em uma sequência.Returns an Int64 that represents the number of elements in a sequence.

Overloads

LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

Retorna um Int64 que representa quantos elementos na sequência atendem a uma condição.Returns an Int64 that represents how many elements in a sequence satisfy a condition.

LongCount<TSource>(IEnumerable<TSource>)

Retorna um Int64 que representa o número total de elementos em uma sequência.Returns an Int64 that represents the total number of elements in a sequence.

LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)

Retorna um Int64 que representa quantos elementos na sequência atendem a uma condição.Returns an Int64 that represents how many elements in a sequence satisfy a condition.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static long LongCount(System::Collections::Generic::IEnumerable<TSource> ^ source, Func<TSource, bool> ^ predicate);
public static long LongCount<TSource> (this System.Collections.Generic.IEnumerable<TSource> source, Func<TSource,bool> predicate);
static member LongCount : seq<'Source> * Func<'Source, bool> -> int64
<Extension()>
Public Function LongCount(Of TSource) (source As IEnumerable(Of TSource), predicate As Func(Of TSource, Boolean)) As Long

Type Parameters

TSource

O tipo dos elementos de source.The type of the elements of source.

Parameters

source
IEnumerable<TSource>

Um IEnumerable<T> que contém os elementos a serem contados.An IEnumerable<T> that contains the elements to be counted.

predicate
Func<TSource,Boolean>

Uma função para testar cada elemento em relação a uma condição.A function to test each element for a condition.

Returns

Int64

Um número que representa quantos elementos na sequência atendem à condição na função de predicado.A number that represents how many elements in the sequence satisfy the condition in the predicate function.

Exceptions

source ou predicate é null.source or predicate is null.

O número de elementos correspondentes excede MaxValue.The number of matching elements exceeds MaxValue.

Examples

O exemplo de código a seguir demonstra como usar LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) para contar os elementos em uma matriz que atendem a uma condição.The following code example demonstrates how to use LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) to count the elements in an array that satisfy a condition.

class Pet
{
    public string Name { get; set; }
    public int Age { get; set; }
}

public static void LongCountEx2()
{
    Pet[] pets = { new Pet { Name="Barley", Age=8 },
                   new Pet { Name="Boots", Age=4 },
                   new Pet { Name="Whiskers", Age=1 } };

    const int Age = 3;

    long count = pets.LongCount(pet => pet.Age > Age);

    Console.WriteLine("There are {0} animals over age {1}.", count, Age);
}

/*
 This code produces the following output:

 There are 2 animals over age 3.
*/
Structure Pet
    Public Name As String
    Public Age As Integer
End Structure

Sub LongCountEx2()
    ' Create a list of Pet objects.
    Dim pets As New List(Of Pet)(New Pet() _
                 {New Pet With {.Name = "Barley", .Age = 8},
                  New Pet With {.Name = "Boots", .Age = 4},
                  New Pet With {.Name = "Whiskers", .Age = 1}})

    ' Determine the number of elements in the list
    ' where the pet's age is greater than a constant value (3).
    Const Age As Integer = 3
    Dim count As Long =
pets.LongCount(Function(pet) pet.Age > Age)

    ' Display the result.
    Console.WriteLine($"There are {count} animals over age {Age}")
End Sub

' This code produces the following output:
'
' There are 2 animals over age 3

Remarks

Use esse método em vez de Count quando você espera que o resultado seja maior que MaxValue.Use this method rather than Count when you expect the result to be greater than MaxValue.

Em Visual Basic sintaxe de expressão de consulta, uma cláusula Aggregate Into LongCount() se traduz em uma invocação de LongCount.In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount.

See also

LongCount<TSource>(IEnumerable<TSource>)

Retorna um Int64 que representa o número total de elementos em uma sequência.Returns an Int64 that represents the total number of elements in a sequence.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static long LongCount(System::Collections::Generic::IEnumerable<TSource> ^ source);
public static long LongCount<TSource> (this System.Collections.Generic.IEnumerable<TSource> source);
static member LongCount : seq<'Source> -> int64
<Extension()>
Public Function LongCount(Of TSource) (source As IEnumerable(Of TSource)) As Long

Type Parameters

TSource

O tipo dos elementos de source.The type of the elements of source.

Parameters

source
IEnumerable<TSource>

Um IEnumerable<T> que contém os elementos a serem contados.An IEnumerable<T> that contains the elements to be counted.

Returns

Int64

O número de elementos na sequência de origem.The number of elements in the source sequence.

Exceptions

source é null.source is null.

O número de elementos excede MaxValue.The number of elements exceeds MaxValue.

Examples

O exemplo de código a seguir demonstra como usar LongCount<TSource>(IEnumerable<TSource>) para contar os elementos em uma matriz.The following code example demonstrates how to use LongCount<TSource>(IEnumerable<TSource>) to count the elements in an array.

string[] fruits = { "apple", "banana", "mango",
                      "orange", "passionfruit", "grape" };

long count = fruits.LongCount();

Console.WriteLine("There are {0} fruits in the collection.", count);

/*
 This code produces the following output:

 There are 6 fruits in the collection.
*/
' Create an array of strings.
Dim fruits() As String =
{"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' Get the number of items in the array.
Dim count As Long = fruits.LongCount()

' Display the result.
Console.WriteLine($"There are {count} fruits in the collection.")

' This code produces the following output:
'
' There are 6 fruits in the collection.

Remarks

Use esse método em vez de Count quando você espera que o resultado seja maior que MaxValue.Use this method rather than Count when you expect the result to be greater than MaxValue.

Em Visual Basic sintaxe de expressão de consulta, uma cláusula Aggregate Into LongCount() se traduz em uma invocação de LongCount.In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount.

See also

Applies to