Enumerable.SequenceEqual Methode

Definition

Bestimmt, ob zwei Sequenzen durch einen Gleichheitsvergleich als gleich bestimmt werden.Determines whether two sequences are equal according to an equality comparer.

Überlädt

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

Bestimmt, ob zwei Sequenzen gleich sind, indem die Elemente mithilfe des Standardgleichheitsvergleichs für ihren Typ verglichen werdenDetermines 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>)

Bestimmt, ob zwei Sequenzen gleich sind, indem ihre Elemente mithilfe eines angegebenen IEqualityComparer<T> verglichen werdenDetermines whether two sequences are equal by comparing their elements by using a specified IEqualityComparer<T>.

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

Bestimmt, ob zwei Sequenzen gleich sind, indem die Elemente mithilfe des Standardgleichheitsvergleichs für ihren Typ verglichen werdenDetermines 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

Typparameter

TSource

Der Typ der Elemente der Eingabesequenzen.The type of the elements of the input sequences.

Parameter

first
IEnumerable<TSource>

Ein IEnumerable<T>, das mit second verglichen werden soll.An IEnumerable<T> to compare to second.

second
IEnumerable<TSource>

Ein IEnumerable<T>, das mit der ersten Sequenz verglichen werden sollAn IEnumerable<T> to compare to the first sequence.

Gibt zurück

Boolean

true, wenn die zwei Quellsequenzen von gleicher Länge sind und ihre entsprechenden Elemente durch den Standardgleichheitsvergleich für ihren Typ als gleich bestimmt werden, andernfalls 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.

Ausnahmen

first oder second ist null.first or second is null.

Beispiele

Die folgenden Codebeispiele veranschaulichen, wie verwendet SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) wird, um zu bestimmen, ob zwei Sequenzen gleich sind.The following code examples demonstrate how to use SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) to determine whether two sequences are equal. In den ersten beiden Beispielen bestimmt die-Methode, ob die verglichenen Sequenzen Verweise auf dieselben Objekte enthalten.In the first two examples, the method determines whether the compared sequences contain references to the same objects. Im dritten und vierten Beispiel vergleicht die-Methode die tatsächlichen Daten der Objekte innerhalb der Sequenzen.In the third and fourth examples, the method compares the actual data of the objects within the sequences.

In diesem Beispiel sind die Sequenzen gleich.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")
    Console.WriteLine($"The lists {text} equal.")

End Sub

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

Im folgenden Codebeispiel werden zwei Sequenzen verglichen, die nicht gleich sind.The following code example compares two sequences that are not equal. Beachten Sie, dass die Sequenzen identische Daten enthalten, aber da die Objekte, die Sie enthalten, über unterschiedliche Verweise verfügen, werden die Sequenzen nicht als gleich betrachtet.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")
Console.WriteLine($"The lists {text} equal.")

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

Wenn Sie die eigentlichen Daten der Objekte in den Sequenzen vergleichen möchten, anstatt nur Ihre Verweise zu vergleichen, müssen Sie die IEqualityComparer<T> generische Schnittstelle in der Klasse implementieren.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. Im folgenden Codebeispiel wird gezeigt, wie Sie diese Schnittstelle in einer Hilfsklasse implementieren und die GetHashCode -und-Methoden bereitstellen Equals .The following code example shows how to implement this interface in a helper class and provide GetHashCode and Equals methods.

public class ProductA: IEquatable<ProductA>
{
    public string Name { get; set; }
    public int Code { get; set; }

    public bool Equals(ProductA other)
    {
        if (other is null)
            return false;

        return this.Name == other.Name && this.Code == other.Code;
    }

    public override bool Equals(object obj) => Equals(obj as ProductA);
    public override int GetHashCode() => (Name, Code).GetHashCode();
}
Public Class ProductA
    Inherits IEquatable(Of ProductA)

    Public Property Name As String
    Public Property Code As Integer

    Public Function Equals(ByVal other As ProductA) As Boolean
        If other Is Nothing Then Return False
        Return Me.Name = other.Name AndAlso Me.Code = other.Code
    End Function

    Public Overrides Function Equals(ByVal obj As Object) As Boolean
        Return Equals(TryCast(obj, ProductA))
    End Function

    Public Overrides Function GetHashCode() As Integer
        Return (Name, Code).GetHashCode()
    End Function

End Class

Nachdem Sie diese Schnittstelle implementiert haben, können Sie Sequenzen von ProductA Objekten in der- SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) Methode verwenden, wie im folgenden Beispiel gezeigt: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

Hinweise

Die SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>) -Methode listet die beiden Quell Sequenzen parallel auf und vergleicht entsprechende-Elemente mithilfe des Standard Gleichheits Vergleichs für TSource , Default .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.

Der Standard Gleichheits Vergleich, Default , wird verwendet, um Werte der Typen zu vergleichen.The default equality comparer, Default, is used to compare values of the types. Um einen benutzerdefinierten Datentyp zu vergleichen, müssen Sie die Equals -Methode und die-Methode überschreiben GetHashCode und optional die IEquatable<T> generische-Schnittstelle im benutzerdefinierten Typ implementieren.To compare a custom data type, you need to override the Equals and the GetHashCode methods, and optionally implement the IEquatable<T> generic interface in the custom type. Weitere Informationen finden Sie in den Ausführungen zur Default-Eigenschaft.For more information, see the Default property.

Gilt für:

Produkt Introduced

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

Bestimmt, ob zwei Sequenzen gleich sind, indem ihre Elemente mithilfe eines angegebenen IEqualityComparer<T> verglichen werdenDetermines 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);
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

Typparameter

TSource

Der Typ der Elemente der Eingabesequenzen.The type of the elements of the input sequences.

Parameter

first
IEnumerable<TSource>

Ein IEnumerable<T>, das mit second verglichen werden soll.An IEnumerable<T> to compare to second.

second
IEnumerable<TSource>

Ein IEnumerable<T>, das mit der ersten Sequenz verglichen werden sollAn IEnumerable<T> to compare to the first sequence.

comparer
IEqualityComparer<TSource>

Ein IEqualityComparer<T>, der zum Vergleichen von Elementen verwendet werden soll.An IEqualityComparer<T> to use to compare elements.

Gibt zurück

Boolean

true, wenn die zwei Quellsequenzen von gleicher Länge sind und ihre entsprechenden Elemente gemäß comparer als gleich gelten, andernfalls false.true if the two source sequences are of equal length and their corresponding elements compare equal according to comparer; otherwise, false.

Ausnahmen

first oder second ist null.first or second is null.

Beispiele

Im folgenden Beispiel wird gezeigt, wie ein Gleichheits Vergleich implementiert wird, der in der-Methode verwendet werden kann SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) .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

Nachdem Sie diesen Vergleich implementiert haben, können Sie Sequenzen von Product Objekten in der- SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) Methode verwenden, wie im folgenden Beispiel gezeigt: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

Hinweise

Die SequenceEqual<TSource>(IEnumerable<TSource>, IEnumerable<TSource>, IEqualityComparer<TSource>) -Methode listet die beiden Quell Sequenzen parallel auf und vergleicht die entsprechenden-Elemente mithilfe der angegebenen IEqualityComparer<T> .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>. Wenn comparer null den Wert hat, wird der Standard Gleichheits Vergleich Default verwendet, um Elemente zu vergleichen.If comparer is null, the default equality comparer, Default, is used to compare elements.

Gilt für:

Produkt Introduced