• Article

Queryable.SequenceEqual<TSource> Method (IQueryable<TSource>, IEnumerable<TSource>)

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Determines whether two sequences are equal by using the default equality comparer to compare elements.

Namespace:  System.Linq
Assembly:  System.Core (in System.Core.dll)

Syntax

'Declaration
<ExtensionAttribute> _
Public Shared Function SequenceEqual(Of TSource) ( _
    source1 As IQueryable(Of TSource), _
    source2 As IEnumerable(Of TSource) _
) As Boolean

public static bool SequenceEqual<TSource>(
    this IQueryable<TSource> source1,
    IEnumerable<TSource> source2
)

Type Parameters

  • TSource
    The type of the elements of the input sequences.

Parameters

Return Value

Type: System.Boolean
true if the two source sequences are of equal length and their corresponding elements compare equal; otherwise, false.

Usage Note

In Visual Basic and C#, you can call this method as an instance method on any object of type IQueryable<TSource>. When you use instance method syntax to call this method, omit the first parameter.

Exceptions

Exception Condition
ArgumentNullException

source1 or source2 is nulla null reference (Nothing in Visual Basic).

Remarks

The SequenceEqual<TSource>(IQueryable<TSource>, IEnumerable<TSource>) method generates a MethodCallExpression that represents calling SequenceEqual<TSource>(IQueryable<TSource>, IEnumerable<TSource>) itself as a constructed generic method. It then passes the MethodCallExpression to the Execute<TResult>(Expression) method of the IQueryProvider represented by the Provider property of the source1 parameter.

The query behavior that occurs as a result of executing an expression tree that represents calling SequenceEqual<TSource>(IQueryable<TSource>, IEnumerable<TSource>) depends on the implementation of the type of the source1 parameter. The expected behavior is that it determines if the two source sequences are equal.

Examples

The following code example demonstrates how to use SequenceEqual<TSource>(IQueryable<TSource>, IEnumerable<TSource>) to determine whether two sequences are equal. In this example the sequences are equal.

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

   Shared Sub SequenceEqualEx1()
      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 lists are equal.
      Dim equal As Boolean = pets1.AsQueryable().SequenceEqual(pets2)

      ' Display the output.
      Dim text As String = IIf(equal, "are", "are not")
      outputBlock.Text &= "The lists " & text & " equal." & vbCrLf
   End Sub

   'This code produces the following output:

   'The lists 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 };

            // Determine if the lists are equal.
            bool equal = pets1.AsQueryable().SequenceEqual(pets2);

            outputBlock.Text += String.Format(
                "The lists {0} equal.",
                equal ? "are" : "are not") + "\n";
         }

         /*
             This code produces the following output:

             The lists are equal.
         */

The following code example compares two sequences that are not equal.

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

   Shared Sub SequenceEqualEx2()
      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 lists are equal.
      Dim equal As Boolean = pets1.AsQueryable().SequenceEqual(pets2)

      ' Display the output.
      Dim text As String = IIf(equal, "are", "are not")
      outputBlock.Text &= "The lists " & text & " equal." & vbCrLf
   End Sub

   ' This code produces the following output:

   ' The lists are not 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 } 
                };

            // Determine if the lists are equal.
            bool equal = pets1.AsQueryable().SequenceEqual(pets2);

            outputBlock.Text += String.Format("The lists {0} equal.", equal ? "are" : "are NOT") + "\n";
         }

         /*
             This code produces the following output:

             The lists are NOT equal.
         */

Version Information

Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.