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Active Forums => Programs => Topic started by: Qbee on December 15, 2019, 11:51:02 pm

Title: Function: StrReplace
Post by: Qbee on December 15, 2019, 11:51:02 pm
I made this function, because it seemed it's functionality is needed and there is no entry in the wiki.
Hope it will be useful.

Code: QB64: [Select]
  1. _TITLE "StrReplace"
  2. ' done 2019-12-16
  3. ' by Myself (Karsten Maske)
  4. '
  5. ' StrReplace$ replaces oldChars by newChars in sourceString
  6. '
  7. ' SYNTAX:
  8. ' newString = StrReplace(oldChars, newChars, sourceString)
  9. '
  10. ' sourceString: string to change
  11. ' oldChars: 0 to length of sourceString; longer string returns sourceString
  12. ' newChars: 0 to whatever fits
  13. '
  14. ' Examples:
  15. '
  16. a$ = "Hello world!"
  17. b$ = StrReplace$("e", "a", a$)
  19.  
  20. a$ = "The quick brown fox jumps over the lazy dog."
  21. b$ = StrReplace$("fox", "duck", a$)
  23.  
  24. b$ = StrReplace$(" ", "", a$)
  26.  
  27.  
  28. FUNCTION StrReplace$ (oldChars AS STRING, newChars AS STRING, sourceString AS STRING)
  29.     DIM o AS INTEGER, n AS INTEGER, i AS INTEGER
  30.  
  31.     n = LEN(sourceString)
  32.     o = LEN(oldChars)
  33.     IF n < 1 THEN
  34.         StrReplace$ = ""
  35.         EXIT FUNCTION
  36.     END IF
  37.  
  38.     IF o > n THEN
  39.         StrReplace$ = sourceString
  40.         EXIT FUNCTION
  41.     END IF
  42.  
  43.     IF n = o THEN
  44.         IF sourceString = oldChars THEN
  45.             StrReplace$ = newChars
  46.             EXIT FUNCTION
  47.         END IF
  48.     END IF
  49.  
  50.     StrReplace$ = ""
  51.     FOR i = 1 TO n
  52.         IF i + o <= n THEN
  53.             IF MID$(sourceString, i, o) = oldChars THEN
  54.                 StrReplace$ = StrReplace$ + newChars
  55.                 i = i + o - 1
  56.             ELSE
  57.                 StrReplace$ = StrReplace$ + MID$(sourceString, i, 1)
  58.             END IF
  59.         ELSE
  60.             StrReplace$ = StrReplace$ + MID$(sourceString, i)
  61.             EXIT FUNCTION
  62.         END IF
  63.     NEXT
  64.  
  66.  
Title: Re: Function: StrReplace
Post by: commandvom on December 18, 2019, 09:01:11 am
great!
Title: Re: Function: StrReplace
Post by: Petr on December 28, 2019, 03:37:52 pm
Thank you, it is very usefull for me! Somewhere is very small bug - last character in source string is not replaced. My solution? I add one more space to end the source string and then it work very well!

Thanks!
Title: Re: Function: StrReplace
Post by: bplus on December 28, 2019, 09:41:31 pm
Hi, I think there is something simpler:
Code: QB64: [Select]
  1.  
  2. _TITLE "strReplace$ test" 'b+ 2019-12-28
  3. PRINT strReplace$("hello all", "l", "llllll")
  4.  
  5. FUNCTION strReplace$ (s$, replace$, new$) 'case sensitive
  6.     strReplace$ = s$
  7.     p = INSTR(s$, replace$)
  8.     WHILE p
  9.         strReplace$ = MID$(strReplace$, 1, p - 1) + new$ + MID$(strReplace$, p + LEN(replace$))
  10.         p = INSTR(p + LEN(new$), strReplace$, replace$)
  11.     WEND
  13.  
Title: Re: Function: StrReplace
Post by: Pete on December 31, 2019, 08:20:12 pm
I actually do this type of work extensively in some html replacement projects. To make it easier, I just feed in the entire document to the program, as a single string then parse the crap out of it until all the replacements are made. Here is the simplest of the methods I have used. It's case sensitive, but this cut-down version will not allow for non-replacement actions on larger words, which contain the search word. Most of the code is actually here just to display it nicely to your screen. The function to replace is only 5-lines.

Pete

Code: QB64: [Select]
  1. WIDTH 80, 25
  2. lmargin = 10
  3. rmargin = _WIDTH - 10
  4.  
  5. a$ = "Steve is a great coder who can accomplish some pretty amazing feats, and some even think of Steve as a god. Well, Steve really isn't a god, he's much better. You see a god has to waste too much of his time on mortals, while Steve can use all his time to create amazing Steve creations that are totally Steveriffic!"
  6.  
  7. PRINT: GOSUB printit: PRINT: _DELAY 5
  8.  
  9. srch$ = "Steve"
  10. replace$ = "Pete"
  11. DO WHILE INSTR(a$, srch$)
  12.     a$ = MID$(a$, 1, INSTR(a$, srch$) - 1) + replace$ + MID$(a$, INSTR(a$, srch$) + LEN(srch$))
  14.  
  15. GOSUB printit
  16.  
  18.  
  19. printit:
  20. IF RIGHT$(a$, 1) <> " " THEN a$ = a$ + " "
  21. seed = 1
  22. DO UNTIL INSTR(seed, a$, " ") = 0
  23.     z$ = MID$(a$, seed, rmargin - lmargin + 2)
  24.     IF lmargin = rmargin THEN z$ = MID$(z$, 1, LEN(z$) - 1)
  25.     IF RIGHT$(z$, 1) = " " THEN
  26.         x = LEN(z$)
  27.     ELSE
  28.         x = _INSTRREV(z$, " ")
  29.     END IF
  30.     IF x = 0 THEN x = rmargin - lmargin + 1
  31.     LOCATE , lmargin
  32.     PRINT RTRIM$(MID$(a$, seed, x))
  33.     seed = seed + x
  36.  

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