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finding values in strings
Post by CharlesB on Mar 7th, 2015, 03:14am

This post goes with the one before it, but I wanted to separate it for a reason.

This question is the "easy one" mired within the last post, and any kind soul who might want to help might not see this question that was tagged onto the last "Strings" post.

( As I am now stuck-in-the-mud in trying to make sense of downloading a file, I cannot progress in some of the less mind-numbing coding. I have been on the Wiki site, but it's more than I can process at present.)


But I have a task that has just stumped me.
I know that it is not difficult to solve, but I just can't do it.

Can someone help me to find the values between the commas in a csv string?
I have tried all sorts of combinations of fore next loops, left$, right$ instr, and so, but I'm just stumped.

For example, take this line from a file "10,3,4,5,7,8,12"
How can I get these characters between the commas off of this string and transfer them to string variables?

a$(1) = "10"
a$(2) = "3"
etc?

Thanks so much for any help.
Charles
Re: finding values in strings
Post by Ian Kings on Mar 7th, 2015, 07:34am

Hi Charles,

Have you tried Richard's split function?

I'm sure it was available via the old Yahoo groups forum in the files section, or it might even be already installed as part of BB4W installation as a library.

Code:
      REM. Routine to emulate the SPLIT function available in some BASICs
      REM. Written by Richard Russell, 13-Mar-2009
      REM. Call as follows: num% = FNsplit(str$, delim$, array$())
      REM. Where str$ is the string to be split
      REM.       delim$ is the delimiter at which it should be split
      REM.       array$() is an array to receive the parts
      REM. The returned value is the number of array elements written

      DEF FNsplit(A$, d$, a$())
      LOCAL C%, I%, Q%, R%
      REPEAT
        R% = 0
        REPEAT
          C% = INSTR(A$, d$, R%+1)
          Q% = INSTR(A$, """", R%+1)
          IF Q% IF C% > Q% THEN
            R% = INSTR(A$, """", Q%+1)
            IF R%=0 ERROR 100, "Mismatched quotes"
          ENDIF
        UNTIL (Q% = 0) OR (C% <= Q%)
        IF C% = 0 THEN C% = LEN(A$)+1
        a$(I%) = LEFT$(A$, C%-1)
        A$ = MID$(A$, C%+LEN(d$))
        I% += 1
      UNTIL A$=""
      = I%


Ian
Re: finding values in strings
Post by rtr2 on Mar 7th, 2015, 09:49am

on Mar 7th, 2015, 07:34am, Ian Kings wrote:
Have you tried Richard's split function?
I'm sure it was available via the old Yahoo groups forum in the files section, or it might even be already installed as part of BB4W installation as a library.

FN_split (and its friend FN_join) are in STRINGLIB:

http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#split
http://www.bbcbasic.co.uk/bbcwin/manual/bbcwing.html#join

Richard.
Re: finding values in strings
Post by KenDown on Mar 7th, 2015, 3:52pm

I'm sure the split function is very useful as a general-purpose function which will take any delimiter. However for Charles' question the solution is extremely simple:

a$="10,3,4,5,7,8,12"
REPEAT
i%=INSTR(a$,","):REM Look for the next comma
IFi%>0THEN
PRINTLEFT$(a$,i%-1):REM Print the first portion of the string
a$=MID$(a$,i%+1):REM Discard the first portion of the string
ENDIF
UNTILi%=0
PRINTa$

Needless to say he could do anything he likes with the string. For example, instead of PRINTing it he could extract the value with a%(index%)=VALa$ (or, if he wanted to be pedantic, a%(index%)=VALLEFT$(a$,i%-1)
Re: finding values in strings
Post by CharlesB on Mar 7th, 2015, 4:17pm

O Ken, thank you so much! This will get me by for now until I can better understand functions! I knew the answer had to be simple, but after 10 hours trying I just could not find it.!!


on Mar 7th, 2015, 3:52pm, KenDown wrote:
I'm sure the split function is very useful as a general-purpose function which will take any delimiter. However for Charles' question the solution is extremely simple:

a$="10,3,4,5,7,8,12"
REPEAT
i%=INSTR(a$,","):REM Look for the next comma
IFi%>0THEN
PRINTLEFT$(a$,i%-1):REM Print the first portion of the string
a$=MID$(a$,i%+1):REM Discard the first portion of the string
ENDIF
UNTILi%=0
PRINTa$

Needless to say he could do anything he likes with the string. For example, instead of PRINTing it he could extract the value with a%(index%)=VALa$ (or, if he wanted to be pedantic, a%(index%)=VALLEFT$(a$,i%-1)