Nullable<T>.Equals(Object) Method

Definition

Indicates whether the current Nullable<T> object is equal to a specified object.

public:
 override bool Equals(System::Object ^ other);
public override bool Equals (object other);
override this.Equals : obj -> bool
Public Overrides Function Equals (other As Object) As Boolean

Parameters

other
Object

An object.

Returns

true if the other parameter is equal to the current Nullable<T> object; otherwise, false.

This table describes how equality is defined for the compared values:

Return Value Description
true The HasValue property is false, and the other parameter is null. That is, two null values are equal by definition. -or- The HasValue property is true, and the value returned by the Value property is equal to the other parameter.
false The HasValue property for the current Nullable<T> structure is true, and the other parameter is null. -or- The HasValue property for the current Nullable<T> structure is false, and the other parameter is not null. -or- The HasValue property for the current Nullable<T> structure is true, and the value returned by the Value property is not equal to the other parameter.

Examples

The following code example determines whether an object and a Nullable<T> object are equal to the current Nullable<T> object.

// This code example demonstrates the Nullable<T>.Equals 
// methods.

using System;

class Sample 
{
    public static void Main() 
    {
    int? nullInt1 = 100;
    int? nullInt2 = 200;
    object myObj;

// Determine if two nullable of System.Int32 values are equal.
// The nullable objects have different values.
    Console.Write("1) nullInt1 and nullInt2 ");
    if (nullInt1.Equals(nullInt2))
        Console.Write("are");
    else
        Console.Write("are not");
    Console.WriteLine(" equal.");

// Determine if a nullable of System.Int32 and an object 
// are equal. The object contains the boxed value of the
// nullable object.

    myObj = (object)nullInt1;
    Console.Write("2) nullInt1 and myObj ");
    if (nullInt1.Equals(myObj))
        Console.Write("are");
    else
        Console.Write("are not");
    Console.WriteLine(" equal.");
    }
}

/*
This code example produces the following results:

1) nullInt1 and nullInt2 are not equal.
2) nullInt1 and myObj are equal.

*/
' This code example demonstrates the Nullable(Of T).Equals 
' methods.

Class Sample
    Public Shared Sub Main() 
        Dim nullInt1 As Nullable(Of Integer) = 100 
        Dim nullInt2 As Nullable(Of Integer) = 200
        Dim myObj As Object
        
    ' Determine if two nullable of System.Int32 values are equal. 
    ' The nullable objects have different values.
        Console.Write("1) nullInt1 and nullInt2 ")
        If nullInt1.Equals(nullInt2) Then
            Console.Write("are")
        Else
            Console.Write("are not")
        End If
        Console.WriteLine(" equal.")
        
    ' Determine if a nullable of System.Int32 and an object 
    ' are equal. The object contains the boxed value of the
    ' nullable object.
        myObj = CType(nullInt1, Object)
        Console.Write("2) nullInt1 and myObj ")
        If nullInt1.Equals(myObj) Then
            Console.Write("are")
        Else
            Console.Write("are not")
        End If
        Console.WriteLine(" equal.")
    End Sub
End Class

'
'This code example produces the following results:
'
'1) nullInt1 and nullInt2 are not equal.
'2) nullInt1 and myObj are equal.
'

Remarks

If the HasValue property of the current Nullable<T> structure is true and the other argument is not null, equality is determined by passing the other parameter to the Equals method of the underlying value of the current Nullable<T> structure.

Applies to