Author Topic: There is definitely an error but for the life of me I can't see it  (Read 5480 times)

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Offline Jaze

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I'm trying to test whether a given string is in the format of a call time. Call times are either H:MM:SS or MM:SS or M:SS
I keep getting a result of TRUE for "Cheese" and other seemingly random strings. I just don't know what the error is
Code: QB64: [Select]
  1. CONST TRUE = 1
  2. CONST FALSE = -1
  3.  
  4. FUNCTION IsCallTime (possibleCallTimeString$)
  5.   rtn = TRUE
  6.   pCt$ = possibleCallTimeString$
  7.   IF LEN(pCt$) = 4 THEN
  8.     '1234
  9.     'M:SS
  10.     IF MID$(pCt$, 2, 1) <> ":" THEN rtn = FALSE
  11.     n1$ = LEFT$(pCt$, 1)
  12.     IF ASC(n1$) < 48 OR ASC(n1$) > 57 THEN rtn = FALSE
  13.     n2$ = MID$(pCt$, 3, 1)
  14.     IF ASC(n2$) < 48 OR ASC(n2$) > 57 THEN rtn = FALSE
  15.     n3$ = MID$(pCt$, 4, 1)
  16.     IF ASC(n3$) < 48 OR ASC(n3$) > 57 THEN rtn = FALSE
  17.     IF VAL(n1$ + n2$ + n3$) = 0 THEN rtn = FALSE
  18.   ELSEIF LEN(pCt$) = 5 THEN
  19.     '12345
  20.     'MM:SS
  21.     PRINT
  22.     IF MID$(pCt$, 3, 1) <> ":" THEN rtn = FALSE
  23.     n1$ = MID$(pCt$, 1, 1)
  24.     IF ASC(n1$) < 48 OR ASC(n1$) > 57 THEN rtn = FALSE
  25.     n2$ = MID$(pCt$, 2, 1)
  26.     IF ASC(n2$) < 48 OR ASC(n2$) > 57 THEN rtn = FALSE
  27.     n3$ = MID$(pCt$, 4, 1)
  28.     IF ASC(n3$) < 48 OR ASC(n3$) > 57 THEN rtn = FALSE
  29.     n4$ = MID$(pCt$, 5, 1)
  30.     IF ASC(n4$) < 48 OR ASC(n4$) > 57 THEN rtn = FALSE
  31.     IF VAL(n1$ + n2$ + n3$ + n$4) = 0 THEN rtn = FALSE
  32.   ELSEIF LEN(pCt$) = 7 THEN
  33.     '1234567
  34.     'H:MM:SS
  35.     IF MID$(pCt$, 2, 1) <> ":" THEN rtn = FALSE
  36.     IF MID$(pCt$, 5, 1) <> ":" THEN rtn = FALSE
  37.     n1$ = MID$(pCt$, 1, 1)
  38.     IF ASC(n1$) < 48 OR ASC(n1$) > 57 THEN rtn = FALSE
  39.     n2$ = MID$(pCt$, 3, 1)
  40.     IF ASC(n2$) < 48 OR ASC(n2$) > 57 THEN rtn = FALSE
  41.     n3$ = MID$(pCt$, 4, 1)
  42.     IF ASC(n3$) < 48 OR ASC(n3$) > 57 THEN rtn = FALSE
  43.     n4$ = MID$(pCt$, 6, 1)
  44.     IF ASC(n4$) < 48 OR ASC(n4$) > 57 THEN rtn = FALSE
  45.     n5$ = MID$(pCt$, 7, 1)
  46.     IF ASC(n5$) < 48 OR ASC(n5$) > 57 THEN rtn = FALSE
  47.     IF VAL(n1$ + n2$ + n3$ + n4$ + n5$) = 0 THEN rtn = FALSE
  48.   END IF
  49.   IsCallTime = rtn

Offline bplus

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Re: There is definitely an error but for the life of me I can't see it
« Reply #1 on: March 17, 2022, 08:15:41 pm »
You might have more luck with False = 0 and True = -1

Don't even set the rtn until you know it's True.


Does this work for you?
Code: QB64: [Select]
  1. Const TRUE = -1
  2. Const FALSE = 0
  3.  
  4.     Input "Test an call hour: "; test$
  5.     Print IsCallTime(test$)
  6.     Print
  7. Loop Until test$ = ""
  8.  
  9. Function IsCallTime (possibleCallTimeString$)
  10.  
  11.     pCt$ = possibleCallTimeString$
  12.     If Len(pCt$) = 4 Then
  13.         '1234
  14.         'M:SS
  15.         If Mid$(pCt$, 2, 1) = ":" Then
  16.             n1$ = Left$(pCt$, 1)
  17.             If Asc(n1$) >= 48 And Asc(n1$) <= 57 Then
  18.                 n2$ = Mid$(pCt$, 3, 1)
  19.                 If Asc(n2$) >= 48 And Asc(n2$) <= 57 Then
  20.                     n3$ = Mid$(pCt$, 4, 1)
  21.                     If Asc(n3$) >= 48 And Asc(n3$) <= 57 Then
  22.                         If Val(n1$ + n2$ + n3$) <> 0 Then rtn = TRUE
  23.                     End If
  24.                 End If
  25.             End If
  26.         End If
  27.     ElseIf Len(pCt$) = 5 Then
  28.         '12345
  29.         'MM:SS
  30.         Print
  31.         If Mid$(pCt$, 3, 1) = ":" Then
  32.             n1$ = Mid$(pCt$, 1, 1)
  33.             If Asc(n1$) >= 48 And Asc(n1$) <= 57 Then
  34.                 n2$ = Mid$(pCt$, 2, 1)
  35.                 If Asc(n2$) >= 48 And Asc(n2$) <= 57 Then
  36.                     n3$ = Mid$(pCt$, 4, 1)
  37.                     If Asc(n3$) >= 48 And Asc(n3$) <= 57 Then
  38.                         n4$ = Mid$(pCt$, 5, 1)
  39.                         If Asc(n4$) >= 48 And Asc(n4$) <= 57 Then
  40.                             If Val(n1$ + n2$ + n3$ + n$4) <> 0 Then rtn = TRUE
  41.                         End If
  42.                     End If
  43.                 End If
  44.             End If
  45.         End If
  46.  
  47.     ElseIf Len(pCt$) = 7 Then
  48.         '1234567
  49.         'H:MM:SS
  50.         If Mid$(pCt$, 2, 1) = ":" Then  ' edit fix this too!
  51.             If Mid$(pCt$, 5, 1) = ":" Then  'edit fix this too!
  52.                 n1$ = Mid$(pCt$, 1, 1)
  53.                 If Asc(n1$) >= 48 And Asc(n1$) <= 57 Then
  54.                     n2$ = Mid$(pCt$, 3, 1)
  55.                     If Asc(n2$) >= 48 And Asc(n2$) <= 57 Then
  56.                         n3$ = Mid$(pCt$, 4, 1)
  57.                         If Asc(n3$) >= 48 And Asc(n3$) <= 57 Then
  58.                             n4$ = Mid$(pCt$, 6, 1)
  59.                             If Asc(n4$) >= 48 And Asc(n4$) <= 57 Then
  60.                                 n5$ = Mid$(pCt$, 7, 1)
  61.                                 If Asc(n5$) >= 48 And Asc(n5$) <= 57 Then
  62.                                     If Val(n1$ + n2$ + n3$ + n4$ + n5$) <> 0 Then rtn = TRUE
  63.                                 End If
  64.                             End If
  65.                         End If
  66.                     End If
  67.                 End If
  68.             End If
  69.         End If
  70.     End If
  71.     IsCallTime = rtn
  72.  
  73.  

OK I didn't finish flipping < to >= and > to <= in the last case and switch ing Or with and like I did in other 2 cases. OK I think I have em all now?

I don't think you need the add values test.
« Last Edit: March 17, 2022, 08:44:29 pm by bplus »

Marked as best answer by Jaze on March 18, 2022, 09:19:46 am

Offline SMcNeill

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Re: There is definitely an error but for the life of me I can't see it
« Reply #2 on: March 17, 2022, 08:19:26 pm »
The reason is really very simple -- "cheese" is 6 letters.  Your sub only checks to invalidate 4, 5, and 7 letter words that aren't in your associated time format.

You start out assuming the format is TRUE, and then never prove that it's not with anything outside of those 3 possible combinations.

You probably need a:

ELSE
    rtn = FALSE

before the END IF.

For ease of emphasis look at this: 
Code: QB64: [Select]
  1. Function IsCallTime (possibleCallTimeString$)
  2.     rtn = TRUE
  3.     pCt$ = possibleCallTimeString$
  4.     If Len(pCt$) = 4 Then
  5.     ElseIf Len(pCt$) = 5 Then
  6.     ElseIf Len(pCt$) = 7 Then
  7.     End If
  8.     IsCallTime = rtn

If length is 4, or 5, or 7.... then...

"cheese" is a length 6.  It's not going to be in any of those IF statements, so it's going to stay TRUE as you set it beforehand.
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Offline bplus

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Re: There is definitely an error but for the life of me I can't see it
« Reply #3 on: March 17, 2022, 08:41:17 pm »
But what if someone does this 1:72? It would pass tests but be improper m:ss.

Offline SMcNeill

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Re: There is definitely an error but for the life of me I can't see it
« Reply #4 on: March 17, 2022, 08:58:30 pm »
But what if someone does this 1:72? It would pass tests but be improper m:ss.

Try it.  It comes back false.

        n4$ = Mid$(pCt$, 5, 1)
        If Asc(n4$) < 48 Or Asc(n4$) > 57 Then rtn = FALSE

Your 5th character isn't a number from 0 to 9...  It's FALSE.
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Offline luke

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Re: There is definitely an error but for the life of me I can't see it
« Reply #5 on: March 17, 2022, 09:28:14 pm »
You will have a much easier time of things if you start by assuming the input does not match, and only setting the return value to true when it does.

Offline bplus

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Re: There is definitely an error but for the life of me I can't see it
« Reply #6 on: March 17, 2022, 09:52:31 pm »
Try it.  It comes back false.

        n4$ = Mid$(pCt$, 5, 1)
        If Asc(n4$) < 48 Or Asc(n4$) > 57 Then rtn = FALSE

Your 5th character isn't a number from 0 to 9...  It's FALSE.

I did try it and it came back true, I am testing my code fix. Need to add test for val(secs) <= 59 and val(mins) <= 59 or test the tens spot for mins and secs < asc("6"), the later is same amount of checks so go with that.

Offline bplus

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Re: There is definitely an error but for the life of me I can't see it
« Reply #7 on: March 17, 2022, 10:05:25 pm »
Here is new fix:
Code: QB64: [Select]
  1. Const TRUE = -1
  2. Const FALSE = 0
  3.  
  4.     Input "Test an call hour: "; test$
  5.     Print IsCallTime(test$)
  6.     Print
  7. Loop Until test$ = ""
  8.  
  9. Function IsCallTime (possibleCallTimeString$)
  10.  
  11.     pCt$ = possibleCallTimeString$
  12.     If Len(pCt$) = 4 Then
  13.         '1234
  14.         'M:SS
  15.         If Mid$(pCt$, 2, 1) = ":" Then
  16.             n1$ = Left$(pCt$, 1)
  17.             If Asc(n1$) >= 48 And Asc(n1$) <= 57 Then
  18.                 n2$ = Mid$(pCt$, 3, 1)
  19.                 If Asc(n2$) >= 48 And Asc(n2$) <= Asc("6") Then
  20.                     n3$ = Mid$(pCt$, 4, 1)
  21.                     If Asc(n3$) >= 48 And Asc(n3$) <= 57 Then
  22.                         If Val(n1$ + n2$ + n3$) <> 0 Then rtn = TRUE
  23.                     End If
  24.                 End If
  25.             End If
  26.         End If
  27.     ElseIf Len(pCt$) = 5 Then
  28.         '12345
  29.         'MM:SS
  30.         Print
  31.         If Mid$(pCt$, 3, 1) = ":" Then
  32.             n1$ = Mid$(pCt$, 1, 1)
  33.             If Asc(n1$) >= 48 And Asc(n1$) <= Asc("6") Then
  34.                 n2$ = Mid$(pCt$, 2, 1)
  35.                 If Asc(n2$) >= 48 And Asc(n2$) <= 57 Then
  36.                     n3$ = Mid$(pCt$, 4, 1)
  37.                     If Asc(n3$) >= 48 And Asc(n3$) <= Asc("6") Then
  38.                         n4$ = Mid$(pCt$, 5, 1)
  39.                         If Asc(n4$) >= 48 And Asc(n4$) <= 57 Then
  40.                             If Val(n1$ + n2$ + n3$ + n$4) <> 0 Then rtn = TRUE
  41.                         End If
  42.                     End If
  43.                 End If
  44.             End If
  45.         End If
  46.  
  47.     ElseIf Len(pCt$) = 7 Then
  48.         '1234567
  49.         'H:MM:SS
  50.         If Mid$(pCt$, 2, 1) = ":" Then
  51.             If Mid$(pCt$, 5, 1) = ":" Then
  52.                 n1$ = Mid$(pCt$, 1, 1)
  53.                 If Asc(n1$) >= 48 And Asc(n1$) <= 57 Then
  54.                     n2$ = Mid$(pCt$, 3, 1)
  55.                     If Asc(n2$) >= 48 And Asc(n2$) <= Asc("6") Then
  56.                         n3$ = Mid$(pCt$, 4, 1)
  57.                         If Asc(n3$) >= 48 And Asc(n3$) <= 57 Then
  58.                             n4$ = Mid$(pCt$, 6, 1)
  59.                             If Asc(n4$) >= 48 And Asc(n4$) <= Asc("6") Then
  60.                                 n5$ = Mid$(pCt$, 7, 1)
  61.                                 If Asc(n5$) >= 48 And Asc(n5$) <= 57 Then
  62.                                     If Val(n1$ + n2$ + n3$ + n4$ + n5$) <> 0 Then rtn = TRUE
  63.                                 End If
  64.                             End If
  65.                         End If
  66.                     End If
  67.                 End If
  68.             End If
  69.         End If
  70.     End If
  71.     IsCallTime = rtn
  72.  
  73.  

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Still can get rid of testing all digits sum <> 0 for True return.

Offline Jaze

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Re: There is definitely an error but for the life of me I can't see it
« Reply #8 on: March 18, 2022, 01:21:26 pm »
Thank you everyone. taking care of the lengths I didn't account for fixed it. And thank you for reminding me that I need to code for some of the digits between 0 and 6, not 0 to 9. Thanks again