Enumerable.LongCount Method

Definition

시퀀스의 요소 수를 나타내는 Int64를 반환합니다.Returns an Int64 that represents the number of elements in a sequence.

Overloads

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

시퀀스에서 특정 조건에 맞는 요소 수를 나타내는 Int64를 반환합니다.Returns an Int64 that represents how many elements in a sequence satisfy a condition.

LongCount<TSource>(IEnumerable<TSource>)

시퀀스의 총 요소 수를 나타내는 Int64를 반환합니다.Returns an Int64 that represents the total number of elements in a sequence.

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

시퀀스에서 특정 조건에 맞는 요소 수를 나타내는 Int64를 반환합니다.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

source 요소의 형식입니다.The type of the elements of source.

Parameters

source
IEnumerable<TSource>

개수를 셀 요소가 들어 있는 IEnumerable<T>입니다.An IEnumerable<T> that contains the elements to be counted.

predicate
Func<TSource,Boolean>

각 요소를 조건에 대해 테스트하는 함수입니다.A function to test each element for a condition.

Returns

Int64

시퀀스에서 조건자 함수의 조건에 맞는 요소 수를 나타내는 숫자입니다.A number that represents how many elements in the sequence satisfy the condition in the predicate function.

Exceptions

source 또는 predicatenull인 경우source or predicate is null.

일치하는 요소 수가 MaxValue를 초과하는 경우The number of matching elements exceeds MaxValue.

Examples

다음 코드 예제에서는 LongCount<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)를 사용 하 여 조건에 맞는 배열의 요소를 계산 하는 방법을 보여 줍니다.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

결과가 MaxValue보다 큰 경우 Count 대신이 메서드를 사용 합니다.Use this method rather than Count when you expect the result to be greater than MaxValue.

Visual Basic 쿼리 식 구문에서 Aggregate Into LongCount() 절은 LongCount호출로 변환 됩니다.In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount.

See also

LongCount<TSource>(IEnumerable<TSource>)

시퀀스의 총 요소 수를 나타내는 Int64를 반환합니다.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

source 요소의 형식입니다.The type of the elements of source.

Parameters

source
IEnumerable<TSource>

개수를 셀 요소가 들어 있는 IEnumerable<T>입니다.An IEnumerable<T> that contains the elements to be counted.

Returns

Int64

소스 시퀀스의 요소 수입니다.The number of elements in the source sequence.

Exceptions

sourcenull입니다.source is null.

요소 수가 MaxValue를 초과하는 경우The number of elements exceeds MaxValue.

Examples

다음 코드 예제에서는 LongCount<TSource>(IEnumerable<TSource>)를 사용 하 여 배열의 요소 수를 계산 하는 방법을 보여 줍니다.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

결과가 MaxValue보다 큰 경우 Count 대신이 메서드를 사용 합니다.Use this method rather than Count when you expect the result to be greater than MaxValue.

Visual Basic 쿼리 식 구문에서 Aggregate Into LongCount() 절은 LongCount호출로 변환 됩니다.In Visual Basic query expression syntax, an Aggregate Into LongCount() clause translates to an invocation of LongCount.

See also

Applies to