[RESOLVED] quick question

[Pantero]

Hi, does a variable create a memory cell, or is it actually the memory cell, for example:

Dim Answer As DialogResult

This is the explanation I have written for that line of code:

"This line of code uses a Dim (Dimension) statement to declare a variable called ‘Answer’.
This variable creates an object to store the user’s answer to a dialog result."

and this is the explanation that my friend said it was:

"This line of code uses a Dim (Dimension) statement to declare a variable called ‘DialogResult’. This variable is a memory cell to store the user’s answer to the dialog result."

Can anyone tell me which is the right explanation?

Thanks

[dbasnett]

The compiler causes memory to be allocated for a variable at run time.

[Shaggy Hiker]

The variable holds the memory address of a chunk of memory that is sized large enough to hold an object of type DialogResult. The variable does not hold the object itself, nor is the object created by that line. All that is done is that a chunk of memory of the right size is set aside, and the address of that chunk of memory is stored with the name of the variable.

[SJWhiteley]

"This line of code uses a Dim (Dimension) statement to declare a variable called ‘Answer’.
This variable creates an object to store the user’s answer to a dialog result."

Looks correct(ish), to me. However, it's not strictly true. 'It declares a variable called Answer that is of the type DialogResult' is all you can say about the line: nothing more.

It certainly does not declare a variable called DialogResult (so your friends answer is incorrect from that stand point).

With regards to 'memory cell': the declaration does nothing in and of itself. only when that variable is used for the first time in your code is memory actually assigned [edit: this isn't actually strictly true] or used (the 'memory cell' you possibly refer to). Effectively, the variable is a humanly readable mechanism to refer to a specific location in memory.

[Pantero]

I see, so a good explanation would be:

This line of code uses a Dim statement to declare a variable called ‘Answer’. This variable sets aside a chunk of memory, to store the answer to the dialog result"

Is that correct?

[dbasnett]

        'Answer does not exist
        If Answer = Windows.Forms.DialogResult.None Then

        End If
        Dim Answer As DialogResult 'now it does
        'when the statement above is executed Answer = Windows.Forms.DialogResult.None
        If Answer = Windows.Forms.DialogResult.None Then
            Stop
        End If
        Answer = MessageBox.Show("FOO", "BAR")
        'when the statement above is executed Answer = Windows.Forms.DialogResult.OK

[Pantero]

why have you given me a piece of code, dbasnett? I need a simple explanation, if anything I am even more confused now..

[dbasnett]

Then see post# 2 - 4.

[Muddy]

I wouldnt think that it would be strictly correct to say that the variable "does" anything.

The help file definition of Dim looks good to me:
Dim - "Declares and allocates storage space for one or more variables."

And the definition of variable from Wikipedia looks good to me:
"variable is a keyword or phrase (identifier) that is linked to a value stored in the system's memory "

[JuggaloBrotha]

I wouldnt think that it would be strictly correct to say that the variable "does" anything.

The help file definition of Dim looks good to me:
Dim - "Declares and allocates storage space for one or more variables."

And the definition of variable from Wikipedia looks good to me:
"variable is a keyword or phrase (identifier) that is linked to a value stored in the system's memory "

A variable doesn't do anything. It simply sits there and holds the memory address for whatever value that address is holding.

[Shaggy Hiker]

It holds the address of a chunk of memory large enough to hold an object of the declared type. The memory holds Nothing until an object of the correct type is put into it.

[Pantero]

Thanks shaggy thats exactly what I was looking for.