Equality in LINQ



Compares two sentences (enumerable ) and determine are they an exact match or not.

Operator Description C# Query Expression Syntax VB Query Expression Syntax
SequenceEqual Results a Boolean value if two sequences are found to be identical to each other Not Applicable Not Applicable

Example of SequenceEqual - Enumerable.SequenceEqual Method

C#

using System;
using System.Collections.Generic;
using System.Linq;

namespace Operators {
   class SequenceEqual {
      static void Main(string[] args) {
      
         Pet barley = new Pet() { Name = "Barley", Age = 4 };
         Pet boots = new Pet() { Name = "Boots", Age = 1 };
         Pet whiskers = new Pet() { Name = "Whiskers", Age = 6 };

         List<Pet> pets1 = new List<Pet>() { barley, boots };
         List<Pet> pets2 = new List<Pet>() { barley, boots };
         List<Pet> pets3 = new List<Pet>() { barley, boots, whiskers };

         bool equal = pets1.SequenceEqual(pets2);
         bool equal3 = pets1.SequenceEqual(pets3);

         Console.WriteLine("The lists pets1 and pets2 {0} equal.", equal ? "are" :"are not");
         Console.WriteLine("The lists pets1 and pets3 {0} equal.", equal3 ? "are" :"are not");

         Console.WriteLine("\nPress any key to continue.");
         Console.ReadKey();
      }

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

VB

Module Module1
   Sub Main()

      Dim barley As New Pet With {.Name = "Barley", .Age = 4}
      Dim boots As New Pet With {.Name = "Boots", .Age = 1}
      Dim whiskers As New Pet With {.Name = "Whiskers", .Age = 6}

      Dim pets1 As New System.Collections.Generic.List(Of Pet)(New Pet() {barley, boots})
      Dim pets2 As New System.Collections.Generic.List(Of Pet)(New Pet() {barley, boots})
      Dim pets3 As New System.Collections.Generic.List(Of Pet)(New Pet() {barley, boots, whiskers})

      Dim equal As Boolean = pets1.SequenceEqual(pets2)
      Dim equal3 As Boolean = pets1.SequenceEqual(pets3)

      Console.WriteLine("The lists pets1 and pets2 {0} equal.", IIf(equal, "are", "are not"))
      Console.WriteLine("The lists pets1 and pets3 {0} equal.", IIf(equal3, "are", "are not"))

      Console.WriteLine(vbLf & "Press any key to continue.")
      Console.ReadKey()
  
   End Sub

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

When the above code of C# or VB is compiled and executed, it produces the following result −

The lists pets1 and pets2 are equal.
The lists pets1 and pets3 are not equal.

Press any key to continue.
linq_query_operators.htm
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