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+---- Thread: Day 024: LCASE$ (/showthread.php?tid=1232)
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RE: Day 024: LCASE$ - luke - 12-05-2022
(12-04-2022, 01:48 PM)SMcNeill Wrote: A better solution, in a case like this, is to minimize the usage of that slow processing string command, as much as possible.
Code: (Select All)DIM tempArray(UBOUND(Array)) AS STRING
FOR i = 0 TO UBOUND(Array)
tempArray(i) = LCASE$(Array(i))
NEXT
FOR x = 0 TO UBOUND(tempArray)
FOR y = 0 TO UBOUND(tempArray)
IF tempArray(x) < tempArray(y) THEN SWAP tempArray(x), tempArray(y)
NEXT
NEXT
FOR i = 0 TO UBOUND(Array)
Array(i) = tempArray(i)
NEXT
Surely this is a good opportunity to use _StriCmp to keep the code neat while still achieving good performance?
Code: (Select All)
For x = 0 To UBound(Array)
For y = 0 To UBound(Array)
If _StriCmp(Array(x), Array(y)) = -1 Then Swap Array(x), Array(y)
Next
NextRE: Day 024: LCASE$ - mnrvovrfc - 12-05-2022
(12-05-2022, 07:30 AM)luke Wrote: Surely this is a good opportunity to use _StriCmp to keep the code neat while still achieving good performance?I actually went to look that up to see if such a function existed. But why bother with a bubble sort? How many times did Steve call it "yucky" or similar? The original example was only to demonstrate that "LCASE$()" is slow, although not as slow as concatenation.
RE: Day 024: LCASE$ - Pete - 12-05-2022
In regard to _StrCmp, it's a bit like my String Comparison routine I made for string math usage, but that was for comparing numbers. I would imagine I'd have to tweak it some to get it to work like the c/c++ StrCmp function.
For positive whole numbers the longer string is the larger number.
Compare "9" to "111"
Results: 111 > 9
but for StrCmp...
Results: -8 where "111" < "9" because the ASCII value of "1" is 8 less than "9"
So StrCmp is not useful for evaluating numbers and I'd have to write a new, but certainly much simpler function to compare strings in this manner. It seems as simple as ASC() in a loop...
Code: (Select All)
WHILE -1
DO
INPUT "Press 1 to evaluate two numbers or A to evaluate to words: "; ans$
IF ans$ = "" THEN SYSTEM
IF ans$ = "" THEN EXIT WHILE
IF ans$ = "1" OR LCASE$(ans$) = "a" THEN EXIT DO
LOOP
PRINT
SELECT CASE ans$
CASE "1" ' Evaluate numbers.
DO
INPUT "Number 1: "; n: s1$ = LTRIM$(STR$(n))
INPUT "Number 2: "; n: s2$ = LTRIM$(STR$(n))
IF s1$ = "" OR s2$ = "" THEN EXIT DO
gl% = 0: sm_greater_lesser s1$, s2$, gl%
SELECT CASE gl%
CASE -1: PRINT s1$; " < "; s2$
CASE 0: PRINT s1$; " = "; s2$
CASE 1: PRINT s1$; " > "; s2$
END SELECT
PRINT
LOOP
CASE ELSE ' Evaluate words.
DO
LINE INPUT "String 1: "; s1$
LINE INPUT "String 2: "; s2$
IF s1$ = "" AND s2$ = "" THEN EXIT DO
PRINT
x = StrCmp(s1$, s2$)
SELECT CASE SGN(x)
CASE -1: PRINT "StrCmp = "; LTRIM$(STR$(x)); " and "; s1$; " < "; s2$
CASE 0: PRINT "StrCmp = "; LTRIM$(STR$(x)); " and "; s1$; " = "; s2$
CASE 1: PRINT "StrCmp = "; LTRIM$(STR$(x)); " and "; s1$; " > "; s2$
END SELECT
PRINT
LOOP
END SELECT
WEND
END
FUNCTION StrCmp (s1$, s2$)
DO
i = i + 1
IF s1$ = "" OR s2$ = "" THEN
IF LEN(s1$) + LEN(s2$) = 0 THEN x = 0: EXIT DO
IF s1$ = "" THEN x = -ASC(s2$) ELSE x = ASC(s1$)
ELSE
x = ASC(MID$(s1$, i, 1)) - ASC(MID$(s2$, 1))
END IF
LOOP UNTIL x OR i >= LEN(s1$) AND i >= LEN(s2$)
StrCmp = x
END FUNCTION
SUB sm_greater_lesser (stringmatha$, stringmathb$, gl%)
compa$ = stringmatha$: compb$ = stringmathb$ ' So original variables do not get changed.
DO
WHILE -1 ' Falx loop.
IF gl% = 2 THEN EXIT WHILE ' For bypassing sign and decimal adjustments when only positive non-decimal numbers are being evaluated.
' Remove trailing zeros after a decimal point.
IF INSTR(compa$, ".") THEN
DO UNTIL RIGHT$(compa$, 1) <> "0" AND RIGHT$(compa$, 1) <> "." AND RIGHT$(compa$, 1) <> "-"
compa$ = MID$(compa$, 1, LEN(compa$) - 1)
LOOP
END IF
IF INSTR(compb$, ".") THEN
DO UNTIL RIGHT$(compb$, 1) <> "0" AND RIGHT$(compb$, 1) <> "." AND RIGHT$(compb$, 1) <> "-"
compb$ = MID$(compb$, 1, LEN(compb$) - 1)
LOOP
END IF
IF MID$(compa$, 1, 2) = "-0" OR compa$ = "" OR compa$ = "-" THEN compa$ = "0"
IF MID$(compb$, 1, 2) = "-0" OR compb$ = "" OR compb$ = "-" THEN compb$ = "0"
' A - and +
j% = 0: k% = 0
IF LEFT$(compa$, 1) = "-" THEN j% = -1
IF LEFT$(compb$, 1) = "-" THEN k% = -1
IF k% = 0 AND j% THEN gl% = -1: EXIT DO
IF j% = 0 AND k% THEN gl% = 1: EXIT DO
j&& = INSTR(compa$, ".")
k&& = INSTR(compb$, ".")
' A starting decimal and non-decimal.
IF j&& = 0 AND k&& = 1 THEN
IF compa$ = "0" THEN gl% = -1 ELSE gl% = 1
EXIT DO
END IF
IF k&& = 0 AND j&& = 1 THEN
IF compb$ = "0" THEN gl% = 1 ELSE gl% = -1
EXIT DO
END IF
' remove decimals and align.
j2&& = 0: k2&& = 0
IF j&& <> 0 OR k&& <> 0 THEN
IF j&& THEN compa$ = MID$(compa$, 1, INSTR(compa$, ".") - 1) + MID$(compa$, INSTR(compa$, ".") + 1): j2&& = LEN(compa$) - j&& + 1
IF k&& THEN compb$ = MID$(compb$, 1, INSTR(compb$, ".") - 1) + MID$(compb$, INSTR(compb$, ".") + 1): k2&& = LEN(compb$) - k&& + 1
compa$ = compa$ + STRING$(k2&& - j2&&, "0")
compb$ = compb$ + STRING$(j2&& - k2&&, "0")
END IF
EXIT WHILE
WEND
' Remove leading zeros if any.
DO UNTIL LEFT$(compa$, 1) <> "0"
compa$ = MID$(compa$, 2)
LOOP
IF compa$ = "" THEN compa$ = "0"
DO UNTIL LEFT$(compb$, 1) <> "0"
compb$ = MID$(compb$, 2)
LOOP
IF compb$ = "" THEN compb$ = "0"
' Both positive or both negative whole numbers.
SELECT CASE LEN(compa$)
CASE IS < LEN(compb$)
gl% = -1
CASE IS = LEN(compb$)
IF compa$ = compb$ THEN
gl% = 0
ELSEIF compa$ > compb$ THEN gl% = 1
ELSEIF compa$ < compb$ THEN gl% = -1
END IF
CASE IS > LEN(compb$)
gl% = 1
END SELECT
EXIT DO
LOOP
END SUBPete