Enumerable.SequenceEqual Enumerable.SequenceEqual Enumerable.SequenceEqual Enumerable.SequenceEqual Method

定義

等値比較子に従って 2 つのシーケンスが等しいかどうかを判断します。 Determines whether two sequences are equal according to an equality comparer.

オーバーロード

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

要素の型に対して既定の等値比較子を使用して要素を比較することで、2 つのシーケンスが等しいかどうかを判断します。 Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.

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

指定された IEqualityComparer<T> を使用して要素を比較することで、2 つのシーケンスが等しいかどうかを判断します。 Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>.

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)

要素の型に対して既定の等値比較子を使用して要素を比較することで、2 つのシーケンスが等しいかどうかを判断します。 Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static bool SequenceEqual(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second);
public static bool SequenceEqual<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second);
static member SequenceEqual : seq<'Source> * seq<'Source> -> bool
<Extension()>
Public Function SequenceEqual(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource)) As Boolean
型パラメーター
TSource

入力シーケンスの要素の型。 The type of the elements of the input sequences.

パラメーター
first
IEnumerable<TSource>

second と比較する IEnumerable<T> An IEnumerable<T> to compare to second.

second
IEnumerable<TSource>

最初のシーケンスと比較する IEnumerable<T> An IEnumerable<T> to compare to the first sequence.

戻り値

2 つのソース シーケンスが同じ長さで、それらに対応する要素がその型の既定の等値比較子に従って等しい場合は true。それ以外の場合は false true if the two source sequences are of equal length and their corresponding elements are equal according to the default equality comparer for their type; otherwise, false.

例外

first または secondnull です。 first or second is null.

次のコード例を使用する方法を示しますSequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)を 2 つのシーケンスが等しいかどうかを判断します。The following code examples demonstrate how to use SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) to determine whether two sequences are equal. 最初の 2 つの例では、メソッドは、比較対象のシーケンスが同じオブジェクトへの参照を含めるかどうかを決定します。In the first two examples, the method determines whether the compared sequences contain references to the same objects. 3 番目と 4 番目の例では、メソッドは、シーケンス内のオブジェクトの実際のデータを比較します。In the third and fourth examples, the method compares the actual data of the objects within the sequences.

この例では、シーケンスは等しいです。In this example the sequences are equal.

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

public static void SequenceEqualEx1()
{
    Pet pet1 = new Pet { Name = "Turbo", Age = 2 };
    Pet pet2 = new Pet { Name = "Peanut", Age = 8 };

    // Create two lists of pets.
    List<Pet> pets1 = new List<Pet> { pet1, pet2 };
    List<Pet> pets2 = new List<Pet> { pet1, pet2 };

    bool equal = pets1.SequenceEqual(pets2);

    Console.WriteLine(
        "The lists {0} equal.",
        equal ? "are" : "are not");
}

/*
 This code produces the following output:

 The lists are equal.
*/

Class Pet
    Public Name As String
    Public Age As Integer
End Class

Sub SequenceEqualEx1()
    ' Create two Pet objects.
    Dim pet1 As New Pet With {.Name = "Turbo", .Age = 2}
    Dim pet2 As New Pet With {.Name = "Peanut", .Age = 8}

    ' Create two lists of pets.
    Dim pets1 As New List(Of Pet)(New Pet() {pet1, pet2})
    Dim pets2 As New List(Of Pet)(New Pet() {pet1, pet2})

    'Determine if the two lists are equal.
    Dim equal As Boolean = pets1.SequenceEqual(pets2)

    ' Display the output.
    Dim text As String = IIf(equal, "are", "are not")
    MsgBox("The lists " & text & " equal.")

End Sub

' This code produces the following output:
'
' The lists are equal.

次のコード例が等しくない 2 つのシーケンスを比較します。The following code example compares two sequences that are not equal. シーケンスは、同一のデータを含めることが含まれているオブジェクトに異なる参照があるため、シーケンスは考慮されませんと等しいことに注意してください。Note that the sequences contain identical data, but because the objects that they contain have different references, the sequences are not considered equal.

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

public static void SequenceEqualEx2()
{
    Pet pet1 = new Pet() { Name = "Turbo", Age = 2 };
    Pet pet2 = new Pet() { Name = "Peanut", Age = 8 };

    // Create two lists of pets.
    List<Pet> pets1 = new List<Pet> { pet1, pet2 };
    List<Pet> pets2 =
        new List<Pet> { new Pet { Name = "Turbo", Age = 2 }, 
                        new Pet { Name = "Peanut", Age = 8 } };

    bool equal = pets1.SequenceEqual(pets2);

    Console.WriteLine("The lists {0} equal.", equal ? "are" : "are not");
}

/*
 This code produces the following output:

 The lists are not equal.
*/

' Create two Pet objects.
Dim pet1 As New Pet With {.Name = "Turbo", .Age = 2}
Dim pet2 As New Pet With {.Name = "Peanut", .Age = 8}

' Create two lists of pets.
Dim pets1 As New List(Of Pet)()
pets1.Add(pet1)
pets1.Add(pet2)

Dim pets2 As New List(Of Pet)()
pets2.Add(New Pet With {.Name = "Turbo", .Age = 2})
pets2.Add(New Pet With {.Name = "Peanut", .Age = 8})

' Determine if the two lists are equal.
Dim equal As Boolean = pets1.SequenceEqual(pets2)

' Display the output.
Dim text As String = IIf(equal, "are", "are not")
MsgBox("The lists " & text & " equal.")

' This code produces the following output:
'
' The lists are not equal.

実装する必要の参照を比較するだけではなくシーケンス内のオブジェクトの実際のデータを比較する場合、IEqualityComparer<T>クラスでジェネリック インターフェイス。If you want to compare the actual data of the objects in the sequences instead of just comparing their references, you have to implement the IEqualityComparer<T> generic interface in your class. 次のコード例は、ヘルパー クラスでこのインターフェイスを実装し、提供する方法を示しています。GetHashCodeEqualsメソッド。The following code example shows how to implement this interface in a helper class and provide GetHashCode and Equals methods.

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

public class ProductComparer : IEqualityComparer<ProductA>
{

    public bool Equals(ProductA x, ProductA y)
    {
        //Check whether the objects are the same object. 
        if (Object.ReferenceEquals(x, y)) return true;

        //Check whether the products' properties are equal. 
        return x != null && y != null && x.Code.Equals(y.Code) && x.Name.Equals(y.Name);
    }

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

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

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

このインターフェイスを実装した後のシーケンスを使用することができますProductA内のオブジェクト、SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)メソッドを次の例に示すようにします。After you implement this interface, you can use sequences of ProductA objects in the SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) method, as shown in the following example.


ProductA[] storeA = { new ProductA { Name = "apple", Code = 9 }, 
                       new ProductA { Name = "orange", Code = 4 } };

ProductA[] storeB = { new ProductA { Name = "apple", Code = 9 }, 
                       new ProductA { Name = "orange", Code = 4 } };

bool equalAB = storeA.SequenceEqual(storeB);

Console.WriteLine("Equal? " + equalAB);

/*
    This code produces the following output:
    
    Equal? True
*/


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

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

Dim equalAB = storeA.SequenceEqual(storeB)

Console.WriteLine("Equal? " & equalAB)

' This code produces the following output:

' Equal? True

注釈

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>)メソッドは、並列の 2 つのソース シーケンスを列挙しの既定の等値比較子を使用して対応する要素を比較TSourceDefaultします。The SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) method enumerates the two source sequences in parallel and compares corresponding elements by using the default equality comparer for TSource, Default. 既定の等値比較子Default、実装する型の値を比較するために使用、IEqualityComparer<T>ジェネリック インターフェイス。The default equality comparer, Default, is used to compare values of the types that implement the IEqualityComparer<T> generic interface. カスタム データ型を比較する必要がありますをこのインターフェイスを実装し、独自GetHashCodeEquals型のメソッド。To compare a custom data type, you need to implement this interface and provide your own GetHashCode and Equals methods for the type.

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

指定された IEqualityComparer<T> を使用して要素を比較することで、2 つのシーケンスが等しいかどうかを判断します。 Determines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>.

public:
generic <typename TSource>
[System::Runtime::CompilerServices::Extension]
 static bool SequenceEqual(System::Collections::Generic::IEnumerable<TSource> ^ first, System::Collections::Generic::IEnumerable<TSource> ^ second, System::Collections::Generic::IEqualityComparer<TSource> ^ comparer);
public static bool SequenceEqual<TSource> (this System.Collections.Generic.IEnumerable<TSource> first, System.Collections.Generic.IEnumerable<TSource> second, System.Collections.Generic.IEqualityComparer<TSource> comparer);
static member SequenceEqual : seq<'Source> * seq<'Source> * System.Collections.Generic.IEqualityComparer<'Source> -> bool
<Extension()>
Public Function SequenceEqual(Of TSource) (first As IEnumerable(Of TSource), second As IEnumerable(Of TSource), comparer As IEqualityComparer(Of TSource)) As Boolean
型パラメーター
TSource

入力シーケンスの要素の型。 The type of the elements of the input sequences.

パラメーター
first
IEnumerable<TSource>

second と比較する IEnumerable<T> An IEnumerable<T> to compare to second.

second
IEnumerable<TSource>

最初のシーケンスと比較する IEnumerable<T> An IEnumerable<T> to compare to the first sequence.

comparer
IEqualityComparer<TSource>

要素の比較に使用する IEqualityComparer<T> An IEqualityComparer<T> to use to compare elements.

戻り値

2 つのソース シーケンスが同じ長さで、comparer に従ってそれらに対応する要素が等しい場合は true。それ以外の場合は false true if the two source sequences are of equal length and their corresponding elements compare equal according to comparer; otherwise, false.

例外

first または secondnull です。 first or second is null.

次の例で使用できる等値比較子を実装する方法を示しています、SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)メソッド。The following example shows how to implement an equality comparer that can be used in the SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) 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

この比較演算子を実装すると後のシーケンスを使用することができますProduct内のオブジェクト、SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)メソッドを次の例に示すようにします。After you implement this comparer, you can use sequences of Product objects in the SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) method, as shown in the following example.


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

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

bool equalAB = storeA.SequenceEqual(storeB, new ProductComparer());

Console.WriteLine("Equal? " + equalAB);

/*
    This code produces the following output:
    
    Equal? True
*/


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

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

Dim equalAB = storeA.SequenceEqual(storeB, New ProductComparer())

Console.WriteLine("Equal? " & equalAB)

' This code produces the following output:

' Equal? True

注釈

SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>)メソッドは、並列の 2 つのソース シーケンスを列挙し、対応する要素を比較するを使用して、指定IEqualityComparer<T>します。The SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) method enumerates the two source sequences in parallel and compares corresponding elements by using the specified IEqualityComparer<T>. 場合comparernull、既定の等値比較子Default要素を比較するために使用します。If comparer is null, the default equality comparer, Default, is used to compare elements.

適用対象