System.SequenceEquals Method

Determines whether two sequences are equal by comparing the elements by using the default equality comparer for their type.

Syntax

Type Parameters

Parameters

first: An IEnumerable<T> to compare with the second sequence.
second: An IEnumerable<T> to compare with the first sequence.

Return Value

Remarks

Two sequences are considered equal if they are of the same length and if the elements at each corresponding position in the two sequences are equal.

This method uses the default equality comparer to compare elements. For a comparer that you specify, use the SequenceEquals<T>(IEnumerable<T>, IEnumerable<T>, IEqualityComparer<T>) overload.

Exceptions

Example

Type	Condition
`ArgumentNullException`	`first` or `second` is null.

C# Example

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

public class Example
{
    public static void Main(string[] args)
    {
        List<int> numbers1 = new List<int>() { 1, 2, 3 };
        List<int> numbers2 = new List<int>() { 1, 2, 3 };
        List<int> numbers3 = new List<int>() { 1, 2, 4 };
        List<int> numbers4 = new List<int>() { 1, 2 };

        bool isEqual12 = numbers1.SequenceEqual(numbers2); // Using extension method
        bool isEqual13 = System.Linq.Enumerable.SequenceEqual(numbers1, numbers3); // Using static method
        bool isEqual14 = numbers1.SequenceEqual(numbers4);

        Console.WriteLine($"Sequence 1 and Sequence 2 are equal: {isEqual12}"); // Output: True
        Console.WriteLine($"Sequence 1 and Sequence 3 are equal: {isEqual13}"); // Output: False
        Console.WriteLine($"Sequence 1 and Sequence 4 are equal: {isEqual14}"); // Output: False
    }
}

Visual Basic Example

Imports System
Imports System.Collections.Generic
Imports System.Linq

Public Module Module1
    Public Sub Main()
        Dim numbers1 As New List(Of Integer)() From {1, 2, 3}
        Dim numbers2 As New List(Of Integer)() From {1, 2, 3}
        Dim numbers3 As New List(Of Integer)() From {1, 2, 4}
        Dim numbers4 As New List(Of Integer)() From {1, 2}

        Dim isEqual12 As Boolean = numbers1.SequenceEqual(numbers2) ' Using extension method
        Dim isEqual13 As Boolean = System.Linq.Enumerable.SequenceEqual(numbers1, numbers3) ' Using static method
        Dim isEqual14 As Boolean = numbers1.SequenceEqual(numbers4)

        Console.WriteLine($"Sequence 1 and Sequence 2 are equal: {isEqual12}") ' Output: True
        Console.WriteLine($"Sequence 1 and Sequence 3 are equal: {isEqual13}") ' Output: False
        Console.WriteLine($"Sequence 1 and Sequence 4 are equal: {isEqual14}") ' Output: False
    End Sub
End Module

Description