Dodam, że rzuciłem okiem na odpowiedź Chipa Pearsona i pomyślałem, że można ją poprawić nieco pod względem wydajności, więc napisałem własną, która wydaje się być o 40% szybsza (nie krępuj się przetestować siebie). Jest szybszy (1.0E-5
vs 1.7E-5
sekund na cykl), ponieważ wykorzystuje tablice bajtów zamiast rzeczywistych znaków do porównywania wartości. Oto funkcja, która zwraca tablicę ciągów jak Chip Pearsona:
Function SplitMultiDelims2(Text As String, DelimChars As String) As String()
'''
'Function to split a string at multiple charachters
'Use like SplitMultiDelims2("This:is-a,test string", ":-,")
'Returns an array, in that example SplitMultiDelims2("This:is-a,test string", ":-,")(4) would be "test string"
'''
Dim bytes() As Byte
Dim delims() As Byte
Dim i As Long, aub As Long, ub As Long
Dim stack As String
Dim t() As String
Dim tLen As Long
tLen = Len(Text)
If tLen = 0 Then
Exit Function
End If
ReDim t(1 To tLen) 'oversize array to avoid Redim Preserve too often
bytes = StrConv(Text, vbFromUnicode)
delims = StrConv(DelimChars, vbFromUnicode)
ub = UBound(bytes)
For i = 0 To ub
If Contains(delims, bytes(i)) Then
aub = aub + 1
t(aub) = stack
stack = ""
Else
stack = stack & Chr(bytes(i))
End If
Next i
t(aub + 1) = stack
ReDim Preserve t(1 To aub + 1) 'Works marginally faster if you delete this line,
'however it returns an oversized array (which is a problem if you use UBOUND of the result,
'but fine if you are just looking up an indexed value like the 5th string)
SplitMultiDelims2 = t
End Function
'and a 2nd function called by the first one
Function Contains(arr, v As Byte) As Boolean 'checks if Byte v is contained in Byte array arr
Dim rv As Boolean, lb As Long, ub As Long, i As Long
lb = LBound(arr)
ub = UBound(arr)
For i = lb To ub
If arr(i) = v Then
rv = True
Exit For
End If
Next i
Contains = rv
End Function
Oto dziennika testu (jego jest SplitMultiDelims, kopalnia SplitMultiDelims2)
> SplitMultiDelims: 1.76105267188204E-05s per cycle 'this is the important figure
> i = 568064 iterations in 10.00390625 seconds
>Test completed: 08/06/2017 10:23:22
> SplitMultiDelims2: 1.05756701906142E-05s per cycle
>i = 947044 iterations in 10.015625 seconds
>Test completed: 08/06/2017 10:23:32
> SplitMultiDelims2: 1.04176859354441E-05s per cycle
>i = 960656 iterations in 10.0078125 seconds
>Test completed: 08/06/2017 10:23:54
> SplitMultiDelims: 1.76228941673255E-05s per cycle
>i = 567887 iterations in 10.0078125 seconds
>Test completed: 08/06/2017 10:24:04
Run w obu kierunkach, aby uniknąć pisania pamięci niekorzystnie wpływa
poniżej kod
test wykorzystuje Timer
więc niezbyt precyzyjne, ale wystarczająco dobry, aby wykazać różnicę
Sub testSplit()
Dim t As Double, dt As Double
Dim s As String
Dim i As Long
t = Timer: i = 0: dt = 0: s = ""
Do Until dt > 10 'loop for 10 seconds
s = SplitMultiDelims("This:is-a,test string", ":-,")(1)
dt = Timer - t
i = i + 1
Loop
Debug.Print "SplitMultiDelims: " & dt/i & "s per cycle" & vbCrLf & "i = " & i; " iterations in " & dt; " seconds" & vbCrLf & "Test completed: " & Now
t = Timer: i = 0: dt = 0: s = ""
Do Until dt > 10 'loop for 10 seconds
s = SplitMultiDelims2("This:is-a,test string", ":-,")(1)
dt = Timer - t
i = i + 1
Loop
Debug.Print "SplitMultiDelims2: " & dt/i & "s per cycle" & vbCrLf & "i = " & i; " iterations in " & dt; " seconds" & vbCrLf & "Test completed: " & Now
End Sub
jeśli chcesz uniknąć podwójnej przestrzeni, możesz użyć funkcji przycinania – juanora