Nullable<T>.ToString Method

Reference

Definition

Namespace:: System

Assemblies:: mscorlib.dll, System.Runtime.dll

Assemblies:: netstandard.dll, System.Runtime.dll

Assembly:: System.Runtime.dll

Assembly:: mscorlib.dll

Assembly:: netstandard.dll

Source:: Nullable.cs

Source:: Nullable.cs

Source:: Nullable.cs

Important

Some information relates to prerelease product that may be substantially modified before it’s released. Microsoft makes no warranties, express or implied, with respect to the information provided here.

Returns the text representation of the value of the current Nullable<T> object.

public:
 override System::String ^ ToString();

public override string ToString();

public override string? ToString();

override this.ToString : unit -> string

Public Overrides Function ToString () As String

Returns

String

The text representation of the value of the current Nullable<T> object if the HasValue property is true, or an empty string ("") if the HasValue property is false.

Examples

The following code example displays the value of the current Nullable<T> object.

// This code example demonstrates the
// Nullable<T>.ToString method.

using System;

class Sample
{
    public static void Main()
    {
    DateTime? nullableDate;

// Display the current date and time.
    nullableDate = DateTime.Now;
    Display("1)", nullableDate);

// Assign null (Nothing in Visual Basic) to nullableDate, then
// display its value.
    nullableDate = null;
    Display("2)", nullableDate);
    }

// Display the text representation of a nullable DateTime.
    public static void Display(string title, DateTime? dspDT)
    {
    string msg = dspDT.ToString();

    Console.Write("{0} ", title);
    if (String.IsNullOrEmpty(msg))
        Console.WriteLine("The nullable DateTime has no defined value.");
    else
        Console.WriteLine("The current date and time is {0}.", msg);
    }
}

/*
This code example produces the following results:

1) The current date and time is 4/19/2005 8:28:14 PM.
2) The nullable DateTime has no defined value.

*/

// This code example demonstrates the
// Nullable<T>.ToString method.
open System

// Display the text representation of a nullable DateTime.
let display title dspDT =
    let msg = dspDT.ToString()

    printf $"{title} "
    if String.IsNullOrEmpty msg then
        printfn "The nullable DateTime has no defined value."
    else
        printfn $"The current date and time is {msg}."

[<EntryPoint>]
let main _ =
    // Display the current date and time.
    let nullableDate = Nullable DateTime.Now
    display "1)" nullableDate

    // Assign null (Nothing in Visual Basic) to nullableDate, then
    // display its value.
    let nullableDate = Nullable()
    display "2)" nullableDate
    0

// This code example produces the following results:
//     1) The current date and time is 4/19/2005 8:28:14 PM.
//     2) The nullable DateTime has no defined value.

' This code example demonstrates the 
' Nullable<T>.ToString method.

Class Sample
    Public Shared Sub Main() 
        Dim nullableDate As Nullable(Of DateTime)
    ' Display the current date and time.
        nullableDate = DateTime.Now
        Display("1)", nullableDate)
        
    ' Assign null (Nothing in Visual Basic) to nullableDate, then 
    ' display its value.
        nullableDate = Nothing
        Display("2)", nullableDate)
    End Sub

    '  Display the text representation of a nullable DateTime.
    Public Shared Sub Display(ByVal title As String, _
                              ByVal dspDT As Nullable(Of DateTime))
        Dim msg As String = dspDT.ToString()

        Console.Write("{0} ", title)
        If String.IsNullOrEmpty(msg) Then
            Console.WriteLine("The nullable DateTime has no defined value.")
        Else
            Console.WriteLine("The current date and time is {0}.", msg)
        End If
    End Sub
End Class

'This code example produces the following results:
'
'1) The current date and time is 4/19/2005 8:28:14 PM.
'2) The nullable DateTime has no defined value.
'

Remarks

The ToString property returns the string yielded by calling the ToString property of the object returned by the Value property.

Applies to

Продукт	Версии
.NET	Core 1.0, Core 1.1, Core 2.0, Core 2.1, Core 2.2, Core 3.0, Core 3.1, 5, 6, 7, 8, 9, 10
.NET Framework	2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, 4.7, 4.7.1, 4.7.2, 4.8, 4.8.1
.NET Standard	1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 2.0, 2.1
UWP	10.0

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