[RESOLVED] Can't declare a new Random variable

[John_SC]

In the following code

Public Class Form1

    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button1.Click
        Dim rand As New random

        lblRandom.Text = rand.next.tostring
    End Sub
End Class

I get the error refering to the Dim statement, with a blue squiggle under random
"Type Expected"

Do I need a Imports for a specific namespace? I thought this worked in the past.

[dday9]

You should not be declaring a Random object at that scope anyways, you should be declaring it at the Form level and either initializing it at the form level or in the form's load event:

Public Class Form1
    Private r As Random

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        r = New Random
    End Sub

End Class

However, to address your namespace issue, the Random class is apart of the System namespace so it should be imported by default.

[Shaggy Hiker]

If there is a squiggle under random, then there should also be a little spot to click for a dropdown with suggestions. If you need to import a namespace, then it will offer to import the correct namespace as the first option. However, Random is part of the System namespace, so I'm not sure you could have gotten this far if Random wasn't there.

Did you happen to name a variable 'random' somewhere at a higher scope?

In any case, you shouldn't be doing what you are doing. You really shouldn't have more than one random object, or else you could run into problems. Have one Random object at form scope and just use that. If you start creating multiple Random objects, you would have to ensure that there are never two created in the same second, or they will produce identical sequences.

[John_SC]

dday9

I tried your code and I got the same error. So is there any guess why it is not being imported by default? and more importantly how to fix it?

[techgnome]

huh... well, considering it didn't change the case from random to Random, I'd hazard a guess it's not finding it for some reason. Try changing it to Random() <- with the parens, and see if that helps.

-tg

[John_SC]

I just closed down VS2013 (I am using Premium) and created a new project with exactly the same results.

[John_SC]

VS changes Random to random by itself. The parentheses don't help - same error.

[dday9]

If it's changing it to random(lower-cased) then what is probably happening is that you're having a namespace confliction where VS is finding more than one Random class and it's picking which one it thinks that it should be. Try changing it to:

Public Class Form1
    Private r As System.Random

    Private Sub Form1_Load(ByVal sender As Object, ByVal e As EventArgs) Handles MyBase.Load
        r = New System.Random
    End Sub

End Class

And see if that works.

[techgnome]

agreed, if it's changing it to lowercase, you have an object conflict that's taking precedence over the class........ what's the name of your project? By chance is it.... "random"?

-tg

[John_SC]

OK,

The error goes away if I write

    Dim rand As New System.Random()

For kicks, I tried

Imports System
Dim rand As New random()

But the error came back.

While this is not how it is suppose to work, I do have a workaround, so I am marking this resolved.

[John_SC]

It was random. I tried a new app called R and it worked fine. Great guess, and thanks for the help.

[Shaggy Hiker]

I'd strongly suggest that you look further into this. Case correcting is a wonderful thing, partly because it alerts you to issues, as this is doing. There is a reason why this is happening, though what it is will take some investigation. Whatever it is, you really should know about it.

The first thing I would do would be to use Ctrl+F to seek all instances of the word random in the entire project. Look at each one of them. The most likely scenario is that you have used the word for something like a variable name somewhere (if it was used as a class name, then it would be a type, so the warning shouldn't be worded as it was).

Second, are you importing any dlls (or is this code in a dll)? It would be MUCH harder for either of those to cause this kind of trouble. In fact, I'm not sure that it could by accident.

EDIT: Nevermind, you posted as I was writing this. It looks like you found the culprit. The only thing I would say is this (again): Case correcting is a good thing. Add at least one capital letter to every name, then type everything in lower case. If the case isn't corrected, there is a problem that will bite you sooner or later. In this case it was sooner.

[John_SC]

I agree with what you said. In my case I boiled down the app to just creating the random variable - what you saw was the whole code. Very plain vanilla to try to figure out what was going on. That is why it was so confusing to me. I did not realize that the name of the project could cause this problem. Again, thanks for your help.

[techgnome]

The reason is because the Application name become the Root Namespace for the application... for example the FQN for your form would have been random.Form1 ... it changing the R to r was the clue... I luckily guessed that the code was all there was, so the only reason that should happen is if there was a namespace conflict and the only thing that made sense was if the application namespace interfered, which would happen if it happened to be "random". Fortunately you named it random, rather than Random... or we might still be trying to figure it out!

-tg

[SJWhiteley]

This is one reason when encountering the problem is to create a new project using the defaults to paste in some code.