If “not X is nothing then” replacement in vb.net. Looking for better way to represent same condition

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When we want to check not null in vb.net we use "IF Not X Is Nothing Then" but this is very vague to read and understand especially if code is complicated or large. Is there any condition with which we can check the same condition and easy to read or understand?

What I have tried:

reading vb.net articles. Followed some articles on stackoverflow and codeproject but no success.

Posted 10-Aug-17 3:46am

maverick1991

Updated 10-Aug-17 19:40pm

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Maciej Los 11-Aug-17 1:49am

So, check this: Nothing (Visual Basic) | Microsoft Docs[^]

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Ralf Meier · Answer 1 · 2017-08-10T03:54:00

Solution 1

You could also write :

VB

IF x isnot Nothing then ...

but seen from the Content it's the same. But I can't see where this is "very vague" ... it is the way to do it ...

Posted 10-Aug-17 3:54am

Ralf Meier

CPallini · Answer 2 · 2017-08-10T08:01:00

Solution 2

If that doesn't it too much the code performance, then place the condition (the 'ugly code') in a Shared method and give it an appealing name like, for instance, isAVeryGoodAndAliveReference.

Posted 10-Aug-17 8:01am

CPallini

Graeme_Grant · Answer 3 · 2017-08-10T15:05:00

Here is another variation using extension methods:

VB

Imports System.Runtime.CompilerServices

Module Module1

    Private FooBar As Foo = Nothing

    Sub Main()

        If (FooBar.IsNotNull) Then
            ' do something
        End If

    End Sub

End Module

Class Foo
    Public Property Bar As String
End Class

Module NullChecks

    <Extension>
    Function IsNull(Of T As Class)(ByVal obj As T) As Boolean
        Return obj Is Nothing
    End Function

    <Extension>
    Function IsNotNull(Of T As Class)(ByVal obj As T) As Boolean
        Return obj IsNot Nothing
    End Function

End Module

ledtech3 · Answer 4 · 2017-08-10T19:40:00

Solution 4

If x = Nothing then
'Do something (throw error,handle it) or ignore it
else
"Do what it is supposed to do if it is something
EndIf

Probably not the best way but a little more readable.
I use something like this for when a user didn't input data into a text box.

Posted 10-Aug-17 19:40pm

ledtech3

Comments

Maciej Los 11-Aug-17 1:47am

Wrong approach. Check the documentation:
MSDN wrote:"When checking whether a reference (or nullable value type) variable is null, do not use = Nothing or <> Nothing. Always use Is Nothing or IsNot Nothing."

ledtech3 11-Aug-17 9:44am

Thanks for the reference.