format$

[Hanns Ackermann]

Just had a little problem with format$ but wasn't able to fix it.
However, playing around with format$ I repeatedly got strange
results similar to my original one, i.e. different results of x=1/3
depending on the mask$ given in format$(x,mask$). In the following
code I listed the results of msgbox/format$ at the end of the
respective line. The behaviour of the program is similar after
substituting ext by single. I feel that the problem was already
discussed somewhere in this forum, but couldn't find anything.
Am I doing anything wrong? I'm using PII/NT4/PB6. Any idea?

Regards, Hanns.

#compile exe

function pbmain() as long

     dim x as ext   ' single: similar results
   
     On Error Goto Er
   
     x=1/3
     msgbox str$(x)                                    ' = .333333333333333
     msgbox format$(x,"##.####################")       ' =0.033333333333333331200
     msgbox format$(x,"##.##################")         ' =0.333333333333333312
     msgbox format$(x," ##.#####################")     ' =0.00333333333333333312000
     msgbox format$(x,"#.#######################^^^^") ' = .333333333333333
     msgbox str$(x)                                    ' =0 !!!!!!!!!!!!!!
     x=x+0.5
     msgbox str$(x)                                    ' =0 !!!!!!!!!!!!!!
     
     exit function
     
Er:: msgbox "ERROR"

end function

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[This message has been edited by Hanns Ackermann (edited August 23, 2000).]

[Lance Edmonds]

Format$() is limited to 18 decimal places... after that you get undefined results which can affect the appearance of the returned strings.

------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>

[Hanns Ackermann]

Thanks Lance,

I didn't found this limitation in my helpfile. But I'm still
wondering about the results of the last two str$(x) ....

Regards, Hanns.


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[Charles Dietz]

Lance, perhaps PowerBasic could truncate the decimal places to 18 as I do
in the code below using MyFormat()

#COMPILE EXE
#DIM ALL
DECLARE FUNCTION MyFormat(x AS EXT, s AS STRING) AS STRING

FUNCTION PBMAIN() AS LONG
   DIM x AS EXT   ' single: similar results
   ON ERROR GOTO Er
   x=1/3
   MSGBOX STR$(x)                                    ' = .333333333333333
   MSGBOX MyFormat(x,"##.######################")    ' = 0.033333333333333331200
   MSGBOX STR$(x)                                    ' No error now
   EXIT FUNCTION
Er:: MSGBOX "ERROR"
END FUNCTION

FUNCTION MyFormat(x AS EXT, s AS STRING) AS STRING
   LOCAL n AS LONG
   n = INSTR(s, ".")
   IF LEN(s) - n > 18 THEN
      s = LEFT$(s, n) + MID$(s, n+1, 18)
   END IF
   FUNCTION = FORMAT$(x, s)
END FUNCTION

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[Lance Edmonds]

I'll ask R&D on your behalf...



------------------
Lance
PowerBASIC Support
mailto:[email protected][email protected]</A>