Redim question

[Frank Brübach]

Hello.. How does Work redim in my example?

Code Select Expand

' test code for array 27-11-2024
uses console

indexbase 1

dim k as long

'Dim As Single a[4] = {1,2,3,4 }

' that's possible below?
Dim As Single a[9],b[9],c[9],x[9] = {10,20,30,40,50,60,70,80,90 }

'dim as single b[4]= {1,2,3,4 }
'dim as single c[4]= {1,2,3,4 }
'dim as single x[4]= {1,2,3,4 }

print " a[4]+b[4]+c[4]+x[4] " + a[4]+b[4]+c[4]+x[4] cr ' ok 40

' how does redim works?

' ReDim single a[5],b[5],c[5],x[5] 
ReDim single a[5] '',b[5],c[5],x[5] ' result 0, doesn't work

printl " a[5] " + ubound(a[5]) cr ' 256

k=ubound(a[5])
printl k cr  ' 256

wait


[Charles Pegge]

Hi Frank,

redim is a macro that does not support multiple declarations, so you need to do each variable individually. Also assign values in a separate line.

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redim single a[5]
redim single b[5]
redim single c[5]

redim single x[5]
x={1,2,3,4,5}


[Frank Brübach]

hello charles, thanks for your reply, I have a second question:
it's possible to get same result without using 'at strptr(st)' with oxygen?

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'
' pointer question with 'dim as byte ba at strptr(st)'

dim as string st = "BATMAN"
  dim as byte ba at strptr(st)
  'ba=>@st
  printl str(ba[3]) " :  " tab chr(ba[3]) cr ' 84 T

printl " next "
For i  = 0 To Len(st)
  Printl ba[i] + tab Chr(ba[i]) cr
Next i

wait

' same result possible without using 'at strptr(st)' possible with oxygen?

dim as string st = "BATMAN"
  'dim as byte ba at strptr(st) ' original
  'ba=>@st
  ' my idea below but doesn't work
  dim as byte ba=>strptr(st) ' @st
  printl str(ba[3]) " :  " tab chr(ba[3]) cr 

wait


[Charles Pegge]

strptr can be used on all string types. It will automatically return the string pointer, But for string and wstring types that are not parameters passed byval, you can use *st instead of strptr(st). However a null string will cause a GPF. So its not worth the risk.

[Frank Brübach]

Hello Charles must nerving again with this example .. I dont understand the Handling of *st

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uses console

' pointer question 2 with 'dim as byte ba at strptr(st)'

' 1) works very well
'
int i
string cr = chr(13)+chr(10)

dim as string st = "BATMAN"
  dim as byte ba at strptr(st)
  printl str(ba[3]) " :  " tab chr(ba[3]) cr ' 84 T

printl " next "
For i  = 0 To Len(st)
  Printl ba[i] + tab Chr(ba[i]) cr
Next i

wait

' 2) doesnt work very well
'
' same result possible like above without using 'at strptr(st)' possible with oxygen?
'
' charles: "you can use *st instead of strptr(st)"
'
' how does it work correct below?
'
dim as string st2 = "BATMAN2"
  'dim as byte ba at strptr(st) ' original ok
 
  dim as byte ba2 *st2 'strptr(st)  ' doesnt work here, sorry
  printl str(ba2[3]) " :  " tab chr(ba2[3]) cr 

wait

'  strptr can be used on all string types. It will automatically return
'  the string pointer, But for string and wstring types that are not
'  parameters passed byval, you can use *st instead of strptr(st).
'  However a null string will cause a GPF. So its not worth the risk


[Charles Pegge]

Code Select Expand

uses console
  dim as string st2 = "BATMAN2"
  '
  'dim as byte ba2 *st2 'strptr(st)  ' doesnt work here, sorry
  'correction:
  dim as byte ba2 at *st2
  'equivalent:
  dim as byte *ba2 : @ba2=*st2
  '
  printl str(ba2[3]) " :  " tab chr(ba2[3]) cr '84
wait