newbie question about global string arrays

[Patrick Harvey]

Hi all - 2 quick questions:

I am using Firefox 2.9 and PB 9 - in the FF_WINMAIN function (that starts first when my program starts), I am trying to define a global string array that I can use throughout my program but I can't find the correct syntax (and yes, I have looked in the help files)...I'm sure it's something idiotic that I am not seeing... I am trying to use:

Global thearray (1 To 20,1 To 20,1 To 4) As String

Why doesn't this line work?

Once this begins working, I'll simply be reading and putting values in the variable using lines like:

thearray(2,5,2)="123"

I was able to get these lines to compile:
Dim thearray(1 To 20,1 To 20,1 To 4) As Global String
thearray(1,1,1)="bingo"

but further in the program when I try to "msgbox thearray(1,1,1)", it wants me to dimension the variable (like it's not global) - arg!

Any ideas how I can dimension this string array variable to be used globally in my little program?

I also need to dimension two string variables (non-arrayed) globally as well if you can comment on that.

Thanks

Patrick

[Paul Squires]

Looks like you are using FireFly, not FireFox

Outside of the FF_WinMain() function you put code like:

Global thearray () As String

Inside the FF_WinMain() function you would put the following:

Dim thearray (1 To 20,1 To 20,1 To 4) As Global String

Check out the "GLOBAL Statement" Help file topic in the PB help file.

[Pedro Ramirez]

Paul, one question:

Doesn't that second declaration of thearray CREATES another global?

When I first began programming in PBWin I made the mistake of declaring global variables outside the PBMAIN sub AND declared them again inside the PBMAIN.

What I really did was to declare two global instances of the same variable. This lead to many hard-to-solve errors until I declared the variables as globals outside the PBAMIN only.

Now I do the same for arrays.

What I do now is the following, without specifying the type inside the PBMAIN:

GLOBAL thearray() AS STRING

PBMAIN

     DIM thearray(1 to 20)

     ... HERE THE CODE ...

END SUB

[Gösta H. Lovgren-2]

Another way is to groupl all Globals together in one Function/Sub.

'Putting the Globals in a function here allows faster access during programming
' can access them via F4 quicker than otherwise (scrolling, etc.)
Function Global_Variables As Long
'*Nearly* all variables are Global. Not good programming practice maybe but this is a standalone program
'  so there's no concern of "cross contamination" and what it does do is allow for more liberal use
'  of Subs and Functions to ease program readability. GHL
'My stuff
'note all "t" variables are Local (except timer stuff, Twinkle_On_Flag), don't make any Global
  'strings here
Global Hdr_Start, Starting_Time, Caption, Hour_in_Day, k, Last_k, Rules(), s, Stasis_Results() As String           
   ' Row Col arrays
  Global nRC() As Byte          
  Global nRCPtr0, nRCPtr1, nRCPtr2, nRCPtr3, nRCPtr4, nRCPtr5, nRCPtr6, nRCPtr7 As Byte Ptr
  Global tRC() As Byte
  Global tRCPtr0, tRCPtr1, tRCPtr2, tRCPtr3, tRCPtr4, tRCPtr5, tRCPtr6, tRCPtr7 As Byte Ptr
 
Global Array_Num, Array_Num_Max, _ ' As Long
 _
       bg_Color_Now, bg_Color, bg_Ctr_Flag,  bg_Color_Chgs_per_Day, bg_Color_Chgs_Today, _
       bg_start_color, bg_Finish_Color, Bg_Color_Dir, _ 
       bg_Change_ctr, bg_Color_R, bg_Color_G, bg_Color_B, _
       bg_Color_Last, Bg_Change_Flag, bg_R_Dir, bg_G_dir, bg_B_dir, _
       Both_Flag, _ 
 _
       Col_Max, Colonies_Added, C, Colony_Centers(), Crown_Flag, Caption_Scroller_Flag, _
       Current_Dot_Color, Clors(), clor, ctr, ctr1, ctr2, ctr3, Col As Long, _
       Char_Height, Char_Width As Single, _
       Color_Ptr, cline_ptr As Long Ptr
 
Global Days_Ctr As Long 
Global flen, fnum, Forts_Added, Finish_Color, First_Round_Flag, flag As Long, _ 
       fle$, fn$, _
       Font_Handle As Dword, _
       Font_Size As Single        
 
Global Gary_Flag, Goldfish_Flag, Generations, gen_check, gen_total_Last, gen_total As Long
Global Hm_Ctr1, Horizontal_Scroll_Flag, hrs As Long
Global LB_tg, Last_Secs, Last_bg_Color, Last_gen_total, last_Scroll_secs, Life_Ctr, Living_Color_Flag As Long, _
       Left_Col() As Byte
Global mins, Max_Colors  As Long
Global num As Long, _
       nline_ptr As Long Ptr
Global Original_Starting_Population As Long
Global Pause_Flag, Pixel_Color_Direction, Pixel_Color_Flag, Pixel_Color As Long, _
       pline_ptr, Pixel_Color_Ptr As Long Ptr
Global Row_Top_Left, Row_Top_Ctr, Row_Top_Right, _
       Row_Mid_Left, Row_Mid_Right, _
       Row_Btm_Left, Row_Btm_Ctr, Row_Btm_Right, _
       Row_Max, R, rnd_dir, Row As Long
Global Spce, Stp, Start_Flag, Scroll_ctr, secs, Secs_Last, Scroll_secs_Last, Seed, Stasis_Range, _
       Slow_Motion_Flag, Start_Color, Sum_ctr(), Stasis_Points_Flag, Stasis_ctr  As Long, _
       sum_Ptr As Long Ptr, _
       Saying_Delay As Long, Saying_Lines(), Sayings(), Saying, Saying_Last As String
Global tmr1, timer_last, tmr, Twinkle_On_Flag As Long, _
       TotPixel_Ptr As Long Ptr
Global Update_Flag, UB_tg As Long, _
       UpDate() As String
 
Global Wrap_Top_or_Bottom, Working_Flag As Long, _
       w_Ptr As Long Ptr
 
Global x_ptr As Long Ptr       
'Gary's stuff so don't use anywhere
Global w,h,ncw,nch,gwin,z,sum,rsx,rsy,x,y,w1,h1,gdc, totpixel As Long
Global tg(), ng() As Byte
Global tgptr, ngptr As Byte Ptr
Global c1,x,y,offset As Long
Global pline, nline, cline As Long
End Function
'

Then

Function PBMain() As Long
  Global_Variables  'assign all Globals
'  Do other stuff here ....

============================================
"All the world's a stage,
and most of us are desperately unrehearsed."
Sean O'Casey
============================================

[Patrick Harvey]

Thanks Paul/others - yep, I meant FireFly :wavey:

I think I have it working now, but it seems in Firefly that I have to add

Dim thearray (1 To 20,1 To 20,1 To 4) As Global String

to each function (ie, for each item (button) clicked where i want to access the global string array)

Sound correct...?

[Dale Yarker]

Do you have to add:
Dim thearray (1 To 20,1 To 20,1 To 4) As Global String
or is:
Dim thearray (1 To 20,1 To 20,1 To 4)
enough?

The PB compiler already knows it is a global string array from the:
GLOBAL thearray() AS STRING
statement.

Inside the function you should only be setting the dimensions and bounds with the DIM statement.

-------------------------
"to each function (ie, for each item (button) clicked where i want to access the global string array)
Sound correct...?"

No, you're defeating the purpose of making it global in the first place. In other functions you just use the array, you don't have to redefine it because it it GLOBAL.

Someone may have mentioned above, but a memory aid (your's, not the computer's) is to prefix all global names with a "g". In this case like:
GLOBAL gTheArray() AS STRING

Cheers,

[Chris Holbrook]

Most of the answers on globals and arrays are already out there, but due to the lack of an efficient indexing system, we keep revisiting them!

Here's another thread on a similar topic. Post #12 answers one of your questions: http://www.powerbasic.com/support/pb...ighlight=array

[Bob Zale]

There are some very serious misconceptions mentioned here, so let me clarify it.

The GLOBAL statement (without dimensions) is used to declare that a particular global array exists. It simply tells the compiler that a particular name should be associated with this particular global array.

Global thearray () As String

GLOBAL does not generate any executable code -- it's an informational entry. It's best to place it at the beginning of the program and can appear outside of a Sub/Function. You can repeat it anywhere in the program as a reminder to yourself that it exists, but these additional copies do not affect the compiler. If you create a LOCAL or STATIC array by the same name, it takes precedence over the GLOBAL in that particular Sub/Function.

The DIM statement (with dimensions) is used to allocate memory for the array. It determines the number of dimensions, and the number of elements in each of them.

DIM thearray (1 To 20,1 To 20,1 To 4) As Global String

You must include the scope (global) and type (string) so the compiler will know exactly which array you are allocating. For example, if you omit the word global, the compiler would have to assume that you were actually creating a second local array, because LOCAL is the default scope. The DIM statement must be located inside a Sub/Function, and must be executed before any element of the array is referenced. If a DIM statement is executed for an array which already has active dimensions, it is ignored.

Best regards,

Bob Zale
PowerBASIC Inc.

[Patrick Harvey]

Thanks Bob/others:

Thanks Bob /everyone:

I really appreciate the help! It's working great now! yea!:wavey:

Patrick

[Michael Mattias]

If a DIM statement is executed for an array which already has active dimensions, it is ignored.

Hmmm... Since the compiler already detects "array not dimensioned" and flags that as an error, I wonder if maybe there shouldn't maybe also be be...

PowerBASIC Console Compiler
PB/CC   Version Something 
Copyright (c) 1998-2008 PowerBasic Inc.
Venice, Florida USA
All Rights Reserved

Error 99999in D:\SOFTWA~1\pbcc50\Work\BUgs\StdErr1.bas(20:014): 
 Array already dimensioned: MyArray

.. compile time error, when a second DIM for the same array appears in a prodedure?

Goodness knows we've seen people confused by "MY DIM () did not work" (because this condition existed and the DIM was ignored).

???

MCM

[Pedro Ramirez]

Ok. After clarifying some concepts (thanks Bob for that) I found that my previos explanation on DIMming arrays is wrong. I went on and check both the PB help file and my commercial application and found that what I really do is to REDIM the array when I first want to set dimensions on it:

First: I declared the array as GLOBAL.

Second: I dimension it inside a procedure but using the REDIM statement so as to keep the array GLOBAL (as declared previously). If I where to use the DIM statement instead, I would end up dimensioning a LOCAL array.

' Declare as global
GLOBAL thearray() AS STRING

PBMAIN

    ' Redim to maintain global scope
    ' incorrect: REDIM thearray(1 to 20)

    ' Correct:
    REDIM thearray(1 to 20) AS GLOBAL STRING

     ... HERE THE CODE ...

END SUB

[Bob Zale]

Your REDIM must also have an AS GLOBAL STRING clause. A MUST. That's a necessity in this case for both DIM and REDIM.

Bob Zale
PowerBASIC Inc.

[Pedro Ramirez]

After my previuos post I decided to test my example, so I build the following code:

#COMPILE EXE
#DIM ALL

GLOBAL MyArray() AS STRING

FUNCTION PBMAIN () AS LONG

      ' incorrect: DIM MyArray(1 TO 5) AS STRING
    
    ' Correct: 
     DIM MyArray(1 TO 5) AS GLOBAL STRING

      MyArray(3) ="third element"
      ShowValue

END FUNCTION


SUB ShowValue
     
     MSGBOX MyArray(3)
     
END SUB

The line "DIM MyArray(1 TO 5) AS STRING" makes all the difference. As shown, MyArray() remains GLOBAL, as it does if I use the REDIM statement or if I ommit the type ("AS STRING"). The compiler "knows" that MyArray, unless otherwise noted, is GLOBAL.

If I change that line to "DIM MyArray(1 TO 5) AS LOCAL STRING" then a new LOCAL array is created and has the same name as the GLOBAL one.
In this case the compiler gives error 461: array no dimensioned (inside sub ShowValue) when I try to compile the program.

So, as Bob pointed out, the only way to declare it is by specifying the scope: "DIM MyArray(1 TO 5) AS GLOBAL STRING".

----------------------------------------------------

Bob, I read your comment after I posted this one, so I corrected it.
Thanks for the warning.