Variables declarations: What's the difference? (RESOLVED)

What's the difference between it:

VB Code:

Public Class Form1
    Inherits System.Windows.Forms.Form
    Dim myVar As String = "Some text" 'Variable declaration here
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        MsgBox(myVar)
    End Sub
End Class

And it:

VB Code:

Public Class Form1
    Inherits System.Windows.Forms.Form
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim myVar As String = "Some text" 'Variable declaration here
        MsgBox(myVar)
    End Sub
End Class

?

Thanks.

the first one is declared as a class level variable, so it can be used throughout the entire class.

The second one is declared within a sub, so it is a block level variable and can only be used within the block or sub it was declared in.

The scope. The first one enables the variable to be used anywhere in the form. The second one means the variable is only valid within the Button click event.

By way of example, here's a code snippet from a project a did last semester in college:

VB Code:

'''''
    'The Timer variable for the progress bar
    Private pinttime As Integer = 0
 
    Private Sub tmrSplash_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles tmrSplash.Tick
        pgrProgress.Value += 1
        pinttime = pinttime + 1
        '''''
        'When the timer hits the maximum value of
        'the progress bar, close the form
        If pinttime = pgrProgress.Maximum Then
            Me.Close()
            tmrSplash.Dispose()
        End If
    End Sub

If the "Private pinttime As Integer = 0" was in the "Private Sub" section, the value would be reset to 0 every time the timer ticked, but since I want the timer to keep increasing, I put the variable before the procedure.

They are correct, I just thought an example might be helpful.

I'd suggest reading a book. Learning the scope of things is very helpful in all languages.

Variables in functions in VB, C++, and most other languages, they are local to that function, it's in that function's scope.

What about CPU and memory usage?


Thanx.

Quote:

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Originally posted by AlvaroF1
What about CPU and memory usage?


Thanx.

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What about them? Learning and using the proper scope will improve memory usage.

Quote:

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Originally posted by AlvaroF1
What about CPU and memory usage?


Thanx.

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:confused: