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Nullable<T>.Equals Method

Silverlight

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

Namespace: System
Assembly: mscorlib (in mscorlib.dll)

public override bool Equals(
	Object other
)

Parameters

other: Type: System.Object
An object.

Return Value

Type: System.Boolean
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.

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.

Remarks

If the HasValue property of the current Nullable<T> structure is true, equality is determined by passing the other parameter to the Equals method of the underlying value of the current Nullable<T> structure.

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 Example
{
   public static void Demo(System.Windows.Controls.TextBlock outputBlock)
   {
      int? nullInt1 = 100;
      int? nullInt2 = 200;
      object myObj;

      // Determine if two nullable of System.Int32 values are equal.
      // The nullable objects have different values.
      outputBlock.Text += "1) nullInt1 and nullInt2 ";
      if (nullInt1.Equals(nullInt2))
         outputBlock.Text += "are";
      else
         outputBlock.Text += "are not";
      outputBlock.Text += " equal." + "\n";

      // 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;
      outputBlock.Text += "2) nullInt1 and myObj ";
      if (nullInt1.Equals(myObj))
         outputBlock.Text += "are";
      else
         outputBlock.Text += "are not";
      outputBlock.Text += " equal." + "\n";
   }
}

/*
This code example produces the following results:

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

*/