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.NET Framework Class Library
NullableTHasValue Property

Gets a value indicating whether the current NullableT object has a valid value of its underlying type.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)
Syntax
Public ReadOnly Property HasValue As [%$TOPIC/sksw8094_en-us_VS_110_2_0_0_0_0%]
public [%$TOPIC/sksw8094_en-us_VS_110_2_0_1_0_0%] HasValue { get; }
public:
property [%$TOPIC/sksw8094_en-us_VS_110_2_0_2_0_0%] HasValue {
	[%$TOPIC/sksw8094_en-us_VS_110_2_0_2_0_1%] get ();
}
member HasValue : [%$TOPIC/sksw8094_en-us_VS_110_2_0_3_0_0%] with get

Property Value

Type: SystemBoolean
true if the current NullableT object has a value; false if the current NullableT object has no value.
Remarks

If the HasValue property is true, the value of the current NullableT object can be accessed with the Value property. Otherwise, attempting to access its value throws an InvalidOperationException exception.

Examples

The following example uses the HasValue property of a Nullable<Integer> object to determine whether it should display the object's Value property or its GetValueOrDefault property.

Module Example
   Public Sub Main()
      Dim n1 As New Nullable(Of Integer)(10)
      Dim n2 As Nullable(Of Integer)
      Dim n3 As New Nullable(Of Integer)(20)
      n3 = Nothing 
      Dim items() As Nullable(Of Integer) = { n1, n2, n3 }

      For Each item In items
         Console.WriteLine("Has a value: {0}", item.HasValue)
         If item.HasValue Then
            Console.WriteLine("Type: {0}", item.GetType().Name)
            Console.WriteLine("Value: {0}", item.Value)
         Else
            Console.WriteLine("Null: {0}", item Is Nothing)
            Console.WriteLine("Default Value: {0}", item.GetValueOrDefault())
         End If
         Console.WriteLine()
      Next                   
   End Sub 
End Module 
' The example displays the following output: 
'       Has a value: True 
'       Type: Int32 
'       Value: 10 
'        
'       Has a value: False 
'       Null: True 
'       Default Value: 0 
'        
'       Has a value: False 
'       Null: True 
'       Default Value: 0
using System;

public class Example
{
   public static void Main()
   {
      Nullable<int> n1 = new Nullable<int>(10);
      Nullable<int> n2 = null;
      Nullable<int> n3 = new Nullable<int>(20);
      n3 = null;
      Nullable<int>[] items = { n1, n2, n3 }; 

      foreach (var item in items) {
         Console.WriteLine("Has a value: {0}", item.HasValue);
         if (item.HasValue) {
            Console.WriteLine("Type: {0}", item.GetType().Name);
            Console.WriteLine("Value: {0}", item.Value);
         }
         else {
            Console.WriteLine("Null: {0}", item == null);
            Console.WriteLine("Default Value: {0}", item.GetValueOrDefault());
         }
         Console.WriteLine();
      }                  
   }
}
// The example displays the following output: 
//       Has a value: True 
//       Type: Int32 
//       Value: 10 
//        
//       Has a value: False 
//       Null: True 
//       Default Value: 0 
//        
//       Has a value: False 
//       Null: True 
//       Default Value: 0
Version Information

.NET Framework

Supported in: 4.5, 4, 3.5, 3.0, 2.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone Silverlight 8.1, Windows Phone Silverlight 8
Platforms

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.