## You should absolutely avoid using `IsNothing()`

Here are **4 reasons** from the article [**IsNothing() VS Is Nothing**][article]


1. Most importantly, `IsNothing(object)` has everything passed to it as an object, even value types!  Since value types cannot be `Nothing`, it’s a completely wasted check.  
Take the following example:

    
 
        Dim i As Integer
        If IsNothing(i) Then
           ' Do something 
        End If

    This will compile and run fine, whereas this:

        Dim i As Integer
        If i Is Nothing Then
            '   Do something 
        End If
 
    Will not compile, instead the compiler will raise the error:

    > 'Is' operator does not accept operands of type 'Integer'.   
    > Operands must be reference or nullable types.

2. `IsNothing(object)` is actually part of part of the `Microsoft.VisualBasic.dll`.  
This is undesirable as you have an unneeded dependency on the VisualBasic library. 

3. Its slow - 33.76% slower in fact (over 1000000000 iterations)!

4. Perhaps personal preference, but `IsNothing()` reads like a [Yoda Condition][yoda].  When you look at a variable you're checking its state, with it as the subject of your investigation.   

    i.e.  does *it* do x? --- **NOT** Is `x`ing a property of *it*?  

    So I think `If a IsNot Nothing` reads better than `If Not IsNothing(a)`

[article]: http://blog.reneorban.com/2011/12/vbnet-isnothing-vs-is-nothing.html
[yoda]: http://blog.codinghorror.com/new-programming-jargon/

Does anyone here use VB.NET and have a strong preference for or against using `IsNothing` as opposed to `Is Nothing` (for example, `If IsNothing(anObject)` or `If anObject Is Nothing...`)?  If so, why?

EDIT: If you think they're both equally acceptable, do you think it's best to pick one and stick with it, or is it OK to mix them?