What is the Difference between Global and Public, Dim and Private variables?

[sirsnorklingtayo]

What is the Difference between Global and Public, Dim and Private variables? in Visual Basic 6.0. Because I am always using Public and Dim but using Global and Private is doing the same thing, is there any differences between these types of declaration scopes???????

Example:

What is the difference:
' In bas Module
Option Explicit

Global gblmyVar1 as Long ' Declared as Global
Public pblmyVar1 as Long ' Declared as Public

' In Form Module

Private prvRecSet as New ADODB.Recordset ' Declared as Private
Dim dimRecSet as New ADODB.Recordset ' Decalred as Dim

Please help, thanks in advance.

[willakawill]

What is the Difference between Global and Public, Dim and Private variables? in Visual Basic 6.0. Because I am always using Public and Dim but using Global and Private is doing the same thing, is there any differences between these types of declaration scopes???????

Example:

What is the difference:
' In bas Module
Option Explicit

Global gblmyVar1 as Long ' Declared as Global
Public pblmyVar1 as Long ' Declared as Public

' In Form Module

Private prvRecSet as New ADODB.Recordset ' Declared as Private
Dim dimRecSet as New ADODB.Recordset ' Decalred as Dim

Please help, thanks in advance.

Hi
Global is not a vb keyword.
The MSDN library says:

Variables declared using the Public statement are available to all procedures in all modules in all applications unless Option Private Module is in effect; in which case, the variables are public only within the project in which they reside.

Caution The Public statement can't be used in a class module to declare a fixed-length string variable.

Use the Public statement to declare the data type of a variable. For example, the following statement declares a variable as an Integer:

Public NumberOfEmployees As Integer

Only use Public if you want your variable to have scope in your entire project.

As for dim:

Variables declared with Dim at the module level are available to all procedures within the module. At the procedure level, variables are available only within the procedure.

Use the Dim statement at module or procedure level to declare the data type of a variable. For example, the following statement declares a variable as an Integer.

Dim NumberOfEmployees As Integer

[hariharanmca]

What is the Difference between Global and Public, Dim and Private variables? in Visual Basic 6.0. Because I am always using Public and Dim but using Global and Private is doing the same thing, is there any differences between these types of declaration scopes???????

Example:

What is the difference:
' In bas Module
Option Explicit

Global gblmyVar1 as Long ' Declared as Global
Public pblmyVar1 as Long ' Declared as Public

' In Form Module

Private prvRecSet as New ADODB.Recordset ' Declared as Private
Dim dimRecSet as New ADODB.Recordset ' Decalred as Dim

Please help, thanks in advance.

Global???
Public - We can access that variable by Direct or Indirectly through all parts of Project
Private - Only a Pirticular part of Access
Dim - Just like Private and Initialize at the time of calling that part

[Killer42]

Global is not a vb keyword.

Ah, how soon we forget... :)

Global is a holdover from earlier versions, and I believe VB still accepts it for backward compatibility. I'm fairly certain it's treated the same as Public.

[willakawill]

Ah, how soon we forget... :)

Global is a holdover from earlier versions, and I believe VB still accepts it for backward compatibility. I'm fairly certain it's treated the same as Public.

I guess you did not try this out before posting :D

[Killer42]

I guess you did not try this out before posting :D

No, I didn't. But I've just tried it now, and it appears to support what I said. Why?

[willakawill]

No, I didn't. But I've just tried it now, and it appears to support what I said. Why?

My copy of VB6 refuses to let me use the global word. Access rejects it too. How about that.

[Killer42]

My copy of VB6 refuses to let me use the global word. Access rejects it too. How about that.

Hm... maybe it's some option I turned on for compatibility? Don't remember.

I assume this was in a module and not a form, right?

(I've just had a look through the options and can't see anything that looks relevant.)

[sirsnorklingtayo]

I see I see, but you mentioned guys about Option Private Module, and I think this is the key to my answer, because in VB6 you are allowed to create multiple projects in just one Project File, Example: I have a project Named MultiProject, under that project I got 3 types of project like prj001,prj002 and prj003. So, what I think is if you will try to declare a variable in BAS Module with GLOBAL statement you can Access that variable in all of your 3 projects, So what do you think guys??? is that a probable answer to my question ?

[sirsnorklingtayo]

About the Option Private Module, I just figured it out that If VB6 implement this kind of Option then I think that is the reason why there is a GLOBAL Statement, So if you will try to disable the Option Private module then Global statement is in effect and you can access your variables with GLOBAL statement in different types of your projects.

Thanks guys I appreciate all your help and Ideas, but if you think this is not the answer you can suggest another, please don't hesitate to post your answers...

[Killer42]

About the Option Private Module, I just figured it out that If VB6 implement this kind of Option then I think that is the reason why there is a GLOBAL Statement, So if you will try to disable the Option Private module then Global statement is in effect and you can access your variables with GLOBAL statement in different types of your projects.

Thanks guys I appreciate all your help and Ideas, but if you think this is not the answer you can suggest another, please don't hesitate to post your answers...

To be honest, I'm a bit lost.

I used to use Global in VB5 and earlier, but have since converted over to using Public. I still have code which says Global, because it was written in an earlier version. Both seem to work just fine, and I don't think I've heard of Option Private Module before.

The problem is, I've had very little experience with multiple projects. The only time I've worked with more than one project is when I'm creating a user control, in which case the "main" project is generally little more than a form with an instance of the control on it for testing. And I've only done this on rare occasions, as I can never find the time to play with this stuff.

[check2000]

Killer42 : I used to use Global in VB5 and earlier, but have since converted over to using Public. I still have code which says Global, because it was written in an earlier version. Both seem to work just fine, and I don't think I've heard of Option Private Module before.

1. there are no more Global in after VB6.
2. if your program is small and works well, you are right that public-private-global do the same thing. is just the range those variable will have.

here is a link. it summarize the use of global variable in VB.NET. works almost the same thant VB6. VB.NET removed the Global keyword and is replaced by a shared variable inside a class. Global Variables in Visual Basic .NET ; Everything you need to know about Global Variable for VB.NET in this single Post.

there is a simple Private-Public article i made. might give a hand: Public vs. Private