Enumerable.Where Method

Definition

조건자에 따라 값의 시퀀스를 필터링합니다.Filters a sequence of values based on a predicate.

Overloads

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

조건자에 따라 값의 시퀀스를 필터링합니다.Filters a sequence of values based on a predicate.

Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)

조건자에 따라 값의 시퀀스를 필터링합니다.Filters a sequence of values based on a predicate. 조건자 함수의 논리에 각 요소의 인덱스가 사용됩니다.Each element's index is used in the logic of the predicate function.

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

조건자에 따라 값의 시퀀스를 필터링합니다.Filters a sequence of values based on a predicate.

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

Type Parameters

TSource

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

Parameters

source
IEnumerable<TSource>

필터링할 IEnumerable<T>입니다.An IEnumerable<T> to filter.

predicate
Func<TSource,Boolean>

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

Returns

IEnumerable<TSource>

입력 시퀀스에서 조건에 맞는 요소가 들어 있는 IEnumerable<T>입니다.An IEnumerable<T> that contains elements from the input sequence that satisfy the condition.

Exceptions

source 또는 predicatenull인 경우source or predicate is null.

Examples

다음 코드 예제에서는 Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)를 사용 하 여 시퀀스를 필터링 하는 방법을 보여 줍니다.The following code example demonstrates how to use Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>) to filter a sequence.

List<string> fruits =
    new List<string> { "apple", "passionfruit", "banana", "mango",
                    "orange", "blueberry", "grape", "strawberry" };

IEnumerable<string> query = fruits.Where(fruit => fruit.Length < 6);

foreach (string fruit in query)
{
    Console.WriteLine(fruit);
}
/*
 This code produces the following output:

 apple
 mango
 grape
*/
' Create a list of strings.
Dim fruits As New List(Of String)(New String() _
                    {"apple", "passionfruit", "banana", "mango",
                     "orange", "blueberry", "grape", "strawberry"})

' Restrict the results to those strings whose 
' length is less than six.
Dim query As IEnumerable(Of String) =
fruits.Where(Function(fruit) fruit.Length < 6)

' Display the results.
Dim output As New System.Text.StringBuilder
For Each fruit As String In query
    output.AppendLine(fruit)
Next
Console.WriteLine(output.ToString())

' This code produces the following output:
'
' apple
' mango
' grape

Remarks

이 메서드는 지연 된 실행을 사용 하 여 구현 됩니다.This method is implemented by using deferred execution. 즉시 반환 값은 작업을 수행 하는 데 필요한 모든 정보를 저장 하는 개체입니다.The immediate return value is an object that stores all the information that is required to perform the action. 이 메서드를 나타내는 쿼리 하거나 호출 하 여 개체 열거 될 때까지 실행 되지 않습니다 해당 GetEnumerator 메서드를 사용 하 여 직접 또는 foreach Visual C# 또는 For Each Visual Basic의 합니다.The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

쿼리 식 구문에서 where (시각적 개체 C#) 또는 Where (Visual Basic) 절은 Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>)의 호출로 변환 됩니다.In query expression syntax, a where (Visual C#) or Where (Visual Basic) clause translates to an invocation of Where<TSource>(IEnumerable<TSource>, Func<TSource,Boolean>).

See also

Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)

조건자에 따라 값의 시퀀스를 필터링합니다.Filters a sequence of values based on a predicate. 조건자 함수의 논리에 각 요소의 인덱스가 사용됩니다.Each element's index is used in the logic of the predicate function.

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

Type Parameters

TSource

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

Parameters

source
IEnumerable<TSource>

필터링할 IEnumerable<T>입니다.An IEnumerable<T> to filter.

predicate
Func<TSource,Int32,Boolean>

각 소스 요소를 조건에 대해 테스트할 함수이며, 이 함수의 두 번째 매개 변수는 소스 요소의 인덱스를 나타냅니다.A function to test each source element for a condition; the second parameter of the function represents the index of the source element.

Returns

IEnumerable<TSource>

입력 시퀀스에서 조건에 맞는 요소가 들어 있는 IEnumerable<T>입니다.An IEnumerable<T> that contains elements from the input sequence that satisfy the condition.

Exceptions

source 또는 predicatenull인 경우source or predicate is null.

Examples

다음 코드 예제에서는 Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>)를 사용 하 여 각 요소의 인덱스를 포함 하는 조건자를 기준으로 시퀀스를 필터링 하는 방법을 보여 줍니다.The following code example demonstrates how to use Where<TSource>(IEnumerable<TSource>, Func<TSource,Int32,Boolean>) to filter a sequence based on a predicate that involves the index of each element.

int[] numbers = { 0, 30, 20, 15, 90, 85, 40, 75 };

IEnumerable<int> query =
    numbers.Where((number, index) => number <= index * 10);

foreach (int number in query)
{
    Console.WriteLine(number);
}
/*
 This code produces the following output:

 0
 20
 15
 40
*/
' Create an array of integers.
Dim numbers() As Integer = {0, 30, 20, 15, 90, 85, 40, 75}

' Restrict the results to those numbers whose
' values are less than or equal to their index times 10.
Dim query As IEnumerable(Of Integer) =
numbers.Where(Function(number, index) number <= index * 10)

' Display the results.
Dim output As New System.Text.StringBuilder
For Each number As Integer In query
    output.AppendLine(number)
Next
Console.WriteLine(output.ToString())

' This code produces the following output:
'
' 0
' 20
' 15
' 40

Remarks

이 메서드는 지연 된 실행을 사용 하 여 구현 됩니다.This method is implemented by using deferred execution. 즉시 반환 값은 작업을 수행 하는 데 필요한 모든 정보를 저장 하는 개체입니다.The immediate return value is an object that stores all the information that is required to perform the action. 이 메서드를 나타내는 쿼리 하거나 호출 하 여 개체 열거 될 때까지 실행 되지 않습니다 해당 GetEnumerator 메서드를 사용 하 여 직접 또는 foreach Visual C# 또는 For Each Visual Basic의 합니다.The query represented by this method is not executed until the object is enumerated either by calling its GetEnumerator method directly or by using foreach in Visual C# or For Each in Visual Basic.

predicate의 첫 번째 인수는 테스트할 요소를 나타냅니다.The first argument of predicate represents the element to test. 두 번째 인수는 source내에서 요소의 0부터 시작 하는 인덱스를 나타냅니다.The second argument represents the zero-based index of the element within source.

Applies to