Windows Dev Center

Nullable<T>.Equals Method

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.

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.

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.

*/


Windows Phone OS

Supported in: 8.1, 8.0, 7.1, 7.0

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