Windows error using &CRLF

[Ian Bayly]

As a newbie experimenting with PB, I was comparing how arrays behaved compared with VB and as part of this wanted to display a message box with each element on a separate line.
Being unsure of the concatenation character I stared off using "&" but got a windows error with the following two lines of code. The error appeared about 2 seconds after code completed, indicating some sort of cleanup routine failed.
sMessage= Ians(0) & $CRLF & Ians(1) & $CRLF & Ians(2) & $CRLF & Ians(3) & $CRLF & Ians(4)
MSGBOX sMessage
Message was:
"Array.exe has encountered a problem and needs to close. We are sorry for the inconvenience" etc etc
If I reduced the incidence of $CRLF thus:
sMessage= Ians(0) & $CRLF & Ians(1) & $CRLF & Ians(2) & $CRLF & Ians(3)
No error.
I changed the "&" to a "+" to see if this changed the result.

It did, It rebooted my PC!!

Scary stuff - What am I doing wrong.

TIA

Ian B

[Dave Biggs]

Most likely an array subscript out of bounds issue.
Try this code.

#DEBUG ERROR ON                  ' NB
#INCLUDE "WIN32API.INC"
Function PbMain()
 Local count As Long, sMessage, sArr As String 
 Dim Ians() As String        
 ON ERROR GOTO ErrorTrap
 Redim Ians(3)                        ' change to(4) to avoid out of bounds * 
  For count = 0 To 4                                '* <- goes out of bounds!
   Ians(count) = "Ians(" + format$(count) + ")"        
  Next
  sMessage = Ians(0) & $CRLF & Ians(1) + $CRLF + Ians(2) + $CRLF + Ians(3) _
             + $CRLF + Ians(4)                      '* <- out of bounds!
  MsgBox sMessage
 Exit Function
 ErrorTrap:
   MsgBox "Error! " + STR$(ERR) +" "+ ERROR$
   ERR=0
   Resume Next                        ' continue execution at line after error
End Function
'------------------/PBMain

#DEBUG ERROR option specifies whether the compiler should generate code that
checks for array boundary and null-pointer errors wherever they may occur.
The default setting is OFF.
When #DEBUG ERROR mode is ON, any attempt to access an array outside of its
boundaries, or attempting to use a null-pointer will generate a
run-time Error 9 ("Subscript/Pointer out of range"),
and the statement itself is not executed.

Good luck

[Michael Mattias]

Did you [RE]DIM Ians() BEFORE you built 'sMessage?'

And, are you using #DEBUG ERROR ON?

I will guarantee there is nothing wrong with the compiler for the code shown.

[Dave Biggs]

Woops MCM and I were posting at the same time!

BTW either concatenation character '&' or '+' can be used as in my example.

[Ian Bayly]

Thanks for your help - I think I have the arrays sorted enough fro my need but I will apply the techniques you suggest
It may answer some questions if I post the complete code below.
#COMPILE EXE
#DIM ALL

FUNCTION PBMAIN () AS LONG
DIM sMessage AS STRING


DIM words(1,2) AS LONG
DIM iI AS INTEGER
DIM lL AS LONG
words(0,0) = 1
words(0,1) = 2
words(0,2) = 3
REDIM PRESERVE WORDS(1,3)
words(0,3) = 4
MSGBOX STR$(Words(0,1))
DO WHILE iI < 5
Words(1,iI)=10 + iI
iI=Ii+1
LOOP
lL=MSGBOX(STR$(Words(1,4)))

REDIM Ians(5) AS STRING
iI=0
DO WHILE iI <= 5
Ians(iI)=CHR$(64+iI)
iI=Ii+1
LOOP
sMessage= Ians(0) & $CRLF & Ians(1) & $CRLF & Ians(2) & $CRLF & Ians(3) & $CRLF & Ians(4)
MSGBOX sMessage
'ARRAY SORT Ians(), DESCEND
'Msgbox Ians(0) + $CRLF + Ians(1) + $CRLF +Ians(2) + $CRLF + Ians(3) + $CRLF + Ians(4)
END FUNCTION

[Gösta H. Lovgren-2]

REDIM PRESERVE WORDS(1,[B]3[/B])[B] '<-- Dimmed to 3[/B]
words(0,3) = 4
MSGBOX STR$(Words(0,1))
DO WHILE [B]iI < 5[/B]
Words(1,iI)=10 + iI '[B]<-- When iI =  4 creates a BOUNDS ERROR[/B]

=========================================
"The man who goes alone can start today;
but he who travels with another
must wait till that other is ready."
Henry David Thoreau (1817-1862)
=========================================

[Michael Mattias]

but I will apply the techniques you suggest...
It may answer some questions if I post the complete code below.

Missing from your program:

#DEBUG ERROR ON 
.....

  ON ERROR GOTO ERRORTRAP
...
ResumePoint: 

...
    EXIT FUNCTION

ERRORTRAP:
 MSGBOX USING$ ("Oops_! Error # &", ERR, ERROR$(ERR)), %MB_ICONHAND, "Programmer Error" 
 RESUME ResumePoint

[Michael Mattias]

I'll give you credit for using ...

#DIM ALL

.. everyone should acquire this habit.

MCM

[Rodney Hicks]

It should be pointed out that there is no error because of the use of $CRLF as the thread topic suggests.

Rod

[Michael Mattias]

I'd like a nickel for every 'error' posted here that wasn't.

[John Petty]

Lighten up fellows, he did say newbie, we all had to learn and I thought this forum was about helping people learn the power of PB

[Michael Mattias]

>and I thought this forum was about helping people learn the power of PB

And I thought it was about helping people learn the power within themselves.

[Ian Bayly]

Careless, careless careless!!
Thanks for all your time & tips

[Rodney Hicks]

John

Lighten up fellows, he did say newbie, we all had to learn and I thought this forum was about helping people learn the power of PB

I posted that so that six months down the road when I(or anyone else) have forgotten about this thread and I create some code where it appears the $CRLF is causing problems and I do a search for a cure-all and end up in this thread, I'll know that I won't find the answer to my problem here, and I can move on to the next thread.

Rod