Enumerable.Contains Enumerable.Contains Enumerable.Contains Enumerable.Contains Method

정의

시퀀스에 지정된 요소가 들어 있는지를 확인합니다.Determines whether a sequence contains a specified element.

오버로드

Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource)

기본 같음 비교자를 사용 하 여 지정된 된 요소 시퀀스에 포함 되는지 여부를 결정 합니다.Determines whether a sequence contains a specified element by using the default equality comparer.

Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>)

지정 된 사용 하 여 지정된 된 요소 시퀀스에 포함 되는지 여부를 결정 IEqualityComparer<T>합니다.Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>.

Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource) Contains<TSource>(IEnumerable<TSource>, TSource)

기본 같음 비교자를 사용 하 여 지정된 된 요소 시퀀스에 포함 되는지 여부를 결정 합니다.Determines whether a sequence contains a specified element by using the default equality comparer.

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

형식 매개 변수

TSource

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

매개 변수

source
IEnumerable<TSource>

값을 찾을 시퀀스입니다.A sequence in which to locate a value.

value
TSource TSource TSource TSource

시퀀스에서 찾을 값입니다.The value to locate in the sequence.

반환

true 소스 시퀀스를 지정 된 값을 가진 요소가 포함 된 경우 그렇지 않으면 false합니다.true if the source sequence contains an element that has the specified value; otherwise, false.

예외

예제

다음 코드 예제에 사용 하는 방법을 보여 줍니다. Contains<TSource>(IEnumerable<TSource>, TSource) 특정 요소를 배열에 포함 되는지 여부를 확인 하려면.The following code example demonstrates how to use Contains<TSource>(IEnumerable<TSource>, TSource) to determine whether an array contains a specific element.

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

string fruit = "mango";

bool hasMango = fruits.Contains(fruit);

Console.WriteLine(
    "The array {0} contain '{1}'.",
    hasMango ? "does" : "does not",
    fruit);

// This code produces the following output:
//
// The array does contain 'mango'.
' Create an array of strings.
Dim fruits() As String = {"apple", "banana", "mango", "orange", "passionfruit", "grape"}

' This is the string to search the array for.
Dim fruit As String = "mango"

' Determine if the array contains the specified string.
Dim hasMango As Boolean = fruits.Contains(fruit)

Dim text As String = IIf(hasMango, "does", "does not")

' Display the output.
MsgBox("The array " & text & " contain " & fruit)

' This code produces the following output:
'
' The array does contain mango

설명

경우 유형의 source 구현 ICollection<T>Contains 해당 구현에서 메서드 결과를 가져옵니다.If the type of source implements ICollection<T>, the Contains method in that implementation is invoked to obtain the result. 그렇지 않으면이 메서드를 확인 하는지 여부를 source 지정된 된 요소를 포함 합니다.Otherwise, this method determines whether source contains the specified element.

열거형에는 일치 하는 요소가 발견 되는 즉시 종료 됩니다.Enumeration is terminated as soon as a matching element is found.

요소는 기본 같음 비교자를 사용 하 여 지정된 된 값으로 비교 Default합니다.Elements are compared to the specified value by using the default equality comparer, Default.

Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>) Contains<TSource>(IEnumerable<TSource>, TSource, IEqualityComparer<TSource>)

지정 된 사용 하 여 지정된 된 요소 시퀀스에 포함 되는지 여부를 결정 IEqualityComparer<T>합니다.Determines whether a sequence contains a specified element by using a specified IEqualityComparer<T>.

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

형식 매개 변수

TSource

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

매개 변수

source
IEnumerable<TSource>

값을 찾을 시퀀스입니다.A sequence in which to locate a value.

value
TSource TSource TSource TSource

시퀀스에서 찾을 값입니다.The value to locate in the sequence.

comparer
IEqualityComparer<TSource>

값을 비교할 같음 비교자입니다.An equality comparer to compare values.

반환

true 소스 시퀀스를 지정 된 값을 가진 요소가 포함 된 경우 그렇지 않으면 false합니다.true if the source sequence contains an element that has the specified value; otherwise, false.

예외

예제

다음 예제에서는에서 사용할 수 있는 같음 비교자를 구현 하는 방법을 보여 줍니다는 Contains 메서드.The following example shows how to implement an equality comparer that can be used in the Contains method.

public class Product
{
    public string Name { get; set; }
    public int Code { get; set; }
}

// Custom comparer for the Product class
class ProductComparer : IEqualityComparer<Product>
{
    // Products are equal if their names and product numbers are equal.
    public bool Equals(Product x, Product y)
    {
       
        //Check whether the compared objects reference the same data.
        if (Object.ReferenceEquals(x, y)) return true;

        //Check whether any of the compared objects is null.
        if (Object.ReferenceEquals(x, null) || Object.ReferenceEquals(y, null))
            return false;

        //Check whether the products' properties are equal.
        return x.Code == y.Code && x.Name == y.Name;
    }

    // If Equals() returns true for a pair of objects 
    // then GetHashCode() must return the same value for these objects.

    public int GetHashCode(Product product)
    {
        //Check whether the object is null
        if (Object.ReferenceEquals(product, null)) return 0;

        //Get hash code for the Name field if it is not null.
        int hashProductName = product.Name == null ? 0 : product.Name.GetHashCode();

        //Get hash code for the Code field.
        int hashProductCode = product.Code.GetHashCode();

        //Calculate the hash code for the product.
        return hashProductName ^ hashProductCode;
    }

}
Public Class Product
    Public Property Name As String
    Public Property Code As Integer
End Class

' Custom comparer for the Product class
Public Class ProductComparer
    Implements IEqualityComparer(Of Product)

    Public Function Equals1(
        ByVal x As Product, 
        ByVal y As Product
        ) As Boolean Implements IEqualityComparer(Of Product).Equals

        ' Check whether the compared objects reference the same data.
        If x Is y Then Return True

        'Check whether any of the compared objects is null.
        If x Is Nothing OrElse y Is Nothing Then Return False

        ' Check whether the products' properties are equal.
        Return (x.Code = y.Code) AndAlso (x.Name = y.Name)
    End Function

    Public Function GetHashCode1(
        ByVal product As Product
        ) As Integer Implements IEqualityComparer(Of Product).GetHashCode

        ' Check whether the object is null.
        If product Is Nothing Then Return 0

        ' Get hash code for the Name field if it is not null.
        Dim hashProductName = 
            If(product.Name Is Nothing, 0, product.Name.GetHashCode())

        ' Get hash code for the Code field.
        Dim hashProductCode = product.Code.GetHashCode()

        ' Calculate the hash code for the product.
        Return hashProductName Xor hashProductCode
    End Function
End Class

이 비교자를 구현한 후의 시퀀스를 사용할 수 있습니다 Product 개체는 Contains 메서드를 다음 예제에서와 같이:After you implement this comparer, you can use a sequence of Product objects in the Contains method, as shown in the following example:


Product[] fruits = { new Product { Name = "apple", Code = 9 }, 
                       new Product { Name = "orange", Code = 4 }, 
                       new Product { Name = "lemon", Code = 12 } };

Product apple = new Product { Name = "apple", Code = 9 };
Product kiwi = new Product {Name = "kiwi", Code = 8 };

ProductComparer prodc = new ProductComparer();

bool hasApple = fruits.Contains(apple, prodc);
bool hasKiwi = fruits.Contains(kiwi, prodc);

Console.WriteLine("Apple? " + hasApple);
Console.WriteLine("Kiwi? " + hasKiwi);

/*
    This code produces the following output:
 
    Apple? True
    Kiwi? False
*/    


Dim fruits() As Product = 
   {New Product With {.Name = "apple", .Code = 9}, 
    New Product With {.Name = "orange", .Code = 4}, 
    New Product With {.Name = "lemon", .Code = 12}}

Dim apple = New Product With {.Name = "apple", .Code = 9}
Dim kiwi = New Product With {.Name = "kiwi", .Code = 8}

Dim prodc As New ProductComparer()

Dim hasApple = fruits.Contains(apple, prodc)
Dim hasKiwi = fruits.Contains(kiwi, prodc)

Console.WriteLine("Apple? " & hasApple)
Console.WriteLine("Kiwi? " & hasKiwi)


' This code produces the following output:
'
' Apple? True
' Kiwi? False

설명

열거형에는 일치 하는 요소가 발견 되는 즉시 종료 됩니다.Enumeration is terminated as soon as a matching element is found.

하는 경우 comparer 됩니다 null, 기본 같음 비교자를 Default, 지정된 된 값으로 요소를 비교 하는 데 사용 됩니다.If comparer is null, the default equality comparer, Default, is used to compare elements to the specified value.

적용 대상