use*_*942 5 excel vba excel-vba multidimensional-array
也许它的星期一,也许我很愚蠢..但我不能为我的生活找到一个很好的方法从2D阵列中的一行获得一维数组.(也许它不是一个"真正的"2D阵列？)
无论如何,我有一个我这样定义的数组: dim myArr(2,4) as variant
我用1到15的值填充它,看起来像:
1,2,3,4,5
6,7,8,9,10
11,12,13,14,15
所以现在我想要的是该阵列的一行.我能弄明白的唯一方法就是做到这一点:
dim temp() as variant
ReDim temp(lbound(myArr,2) to ubound(myArr,2))
For i = 0 To 0
For j = LBound(myArr, 2) To UBound(myArr, 2)
temp(j) = myArr(i, j)
Next
Next
但我不喜欢这样,因为如果阵列变得庞大,那么花费这么多时间可能要长得多.我想我应该能做到:
dim temp as variant
temp = myArr(0) 'since myArr(0) is a 1D array with 5 spots right?
但没有..我得到'错误的维数'错误.
我还回顾了之前的事情并发现了这个问题:如何比较表格中的两个整行和蒂姆托马斯的答案显示了转置的使用,并提到你是否比较了你只使用转置一次的列,但它不起作用..如果我这样做:dim myArr(2,0) as variant转置工作,但不是我现在的方式.
我在其他语言(例如C++和Python)中找到了无数个问题的答案,但我对这两个问题都不熟悉,所以我无法解释它们.
有没有更好的方法呢？还是我坚持这个我不喜欢的双循环？
谢谢!
Tim*_*ams 15
这是一个"切片"二维数组的方法的独立插图:
Sub ArraySlicing()
Dim arr(1 To 5, 1 To 5)
Dim slice
Dim x, y
Dim a As Application
'Populate a sample 2-D array with values...
For y = 1 To 5
For x = 1 To 5
arr(y, x) = "R" & y & ":C" & x
Next x
Next y
'...done setting up sample array
Set a = Application 'this is just to shorten the following lines
'Example 1: get the first "column"
slice = a.Transpose(a.Index(arr, 0, 1))
Debug.Print Join(slice, ", ") 'display what we got
'Example 2: get second "row" (note double transpose)
slice = a.Transpose(a.Transpose(a.Index(arr, 2, 0)))
Debug.Print Join(slice, ", ") 'display what we got
End Sub
Index()为您提供了一个二维数组 - (x,1)或(1,x) - Transpose()将它转换为一维数组.
@dathanm：一个很好的初始方法，但有几点您似乎不清楚：
这是我的版本，任何人都可以根据需要使用。起初它可能看起来很复杂（由于它的灵活性和健壮性检查），但它的使用实际上非常简单，而且速度非常快：
Function ArraySlice(Arr2D As Variant, ByCol As Boolean, SliceIdx As Long) As Variant
'
'Returns a 1D row or column array "slice" of the specified 2D array.
'
'PARAMETERS:
'
' Arr2D The 2D array from which a row/column slice is to be extracted. The passed array may be of
' any data type.
'
' ByCol True = slice a column; False = slice a row.
'
' SliceIdx The array-index of the row or column to be sliced from the 2D array. Note that the meaning
' of SliceIdx value depends on the base of the 2D array's dimensions: a SliceIdx of 1 will be
' the first row/column of a one-based array but the second row/column of a zero-based array.
'
'RETURN VALUES: If successful, returns a sliced 1D row or column (Variant) array. If unsuccessful, returns
' an Empty Variant status. Note that, though an array of any data type may be passed to this
' routine, the variable receiving the returned array must be a Variant because whole-array
' assignment is implemented for Variants only in VB/VBA.
'
'TECHNICAL NOTES:
'
' 1. IMPORTANT: Though arrays-of-arrays are supported by this routine, jagged arrays-of-arrays (which are
' possible in VBA) would be very complex to handle for column-slice operations, so this routine does not
' support them for that case and will throw an error message accordingly. Also, for column-slice
' operations on rectangular arrays-of-arrays, this routine assumes that each row-array has the same
' LBound (0 or 1 or whatever), which is a condition that can be violated in VB but is extremely unusual.
' This routine will throw an error in that case as well.
'
' 2. The Application.Index method, used by this routine has two forms, an Array form and a Reference form.
' When used by this routine in its Array form, an array (as opposed to a worksheet cell-range reference)
' is passed to it and it returns an array as its return value. In this usage, it doesn't actually
' operate on an Excel worksheet range and is therefore very fast, actually faster than any VBA-coded
' equivalent algorithm, because its functionality is implemented by Excel's underlying compiled-code
' engine.
'
' 3. The Index method and the Transpose method are "orientation-aware" with regard to the row/column
' orientation of the passed array argument. For a multi-row and multi-column rectangular array, the
' orientation question is moot but for a single-row or single-column array it isn't. Without those
' methods' orientation-awareness, they would require an additional optional parameter that the calling
' code would have to set (but only for single-row/column arrays) to inform the methods of the otherwise-
' ambiguous orientation of the passed array. Such a design would further complicate the call interface
' as well as the calling code.
'
' Microsoft's solution was to implement the required orientation-awareness by defining single-row arrays
' as a simple 1D array containing that row's elements (i.e. RowValues(col-num)), and defining single-
' column arrays as a degenerate 2D array containing a single column of each row's value for that column
' (i.e. ColValues(row-num, 1)). That is, those methods determine the orientation of a passed single-
' row/column array by simply checking whether it is a 1D array (row) or 2D array (column). And any
' single-row/column array returned by them also conforms to that scheme. (Technically, it treats the
' passed array as an array-of-arrays, regardless of its implementation in VBA, which is consistent with
' how simple 2D arrays are implemented in C/C++, the language of Excel's compiled-code engine.)
'
' Consequently, to get a true 1D array of column values, the Index method's returned (degenerate) 2D
' array may be passed to the Transpose method, to convert its column-orientation to row-orientation in
' the Transpose method's context. But in the calling-code's context, it becomes just an independent
' 1D array containing the specified column's values.
'
'AUTHOR: Peter Straton
'
'*************************************************************************************************************
Const NA As Long = 0
Dim Arr1DSlice As Variant 'NOTE: Some slice operations require a subsequent shift of the sliced array's
'base in order to make it match the corresponding base of the original 2D array,
'in the sliced dimension. But, because this function's ArraySlice variable is a
'Variant that's also the function's return value, you can't just use Redim Preserve
'to change its base. Instead, you must us a local (shiftable) Variant and then
'assign that array to the function's return value before returning.
Dim BaseOffset As Long
Dim ColIdxLBound As Long
Dim ColIdxUBound As Long
Dim i As Long
Dim IndexFncOffset As Long
Dim IsArrayOfArrays As Variant 'Variant: can be Empty (undefined) or Boolean
Dim RowIdxLBound As Long
Dim RowIdxUBound As Long
Arr1DSlice = Empty 'Default: failure status
'First, determine whether Arr2D is a 2D array or array-of-arrays because they are processed differently.
On Error Resume Next
RowIdxLBound = LBound(Arr2D)
If Err <> 0 Then Exit Function 'Not an array, so exit with failure status
RowIdxUBound = UBound(Arr2D)
If RowIdxUBound < RowIdxLBound Then Exit Function 'Is an array but has no values to be sliced
IsArrayOfArrays = IsArray(Arr2D(RowIdxLBound, RowIdxLBound))
If IsEmpty(IsArrayOfArrays) Then IsArrayOfArrays = IsArray(Arr2D(RowIdxLBound))
On Error GoTo 0
'Do the slice operation
With Application
If ByCol Then
If IsArrayOfArrays Then
ColIdxLBound = LBound(Arr2D(RowIdxLBound)) 'Assumes consistent column-index LBounds and UBounds for
ColIdxUBound = UBound(Arr2D(RowIdxLBound)) 'each row in the array-of-arrays, but...
'Ensure that it doesn't have inconsistent column-index LBounds and isn't a jagged array-of-arrays
'(neither of which are supported) by checking each row's column-index bounds.
For i = RowIdxLBound To RowIdxUBound
If LBound(Arr2D(i)) <> ColIdxLBound Then
MsgBox "ArraySlice: Arrays-of-arrays with inconsistent column-index LBounds are not " & _
"supported for column operations.", vbOKOnly + vbCritical, "PROGRAMMING ERROR"
Exit Function
End If
If UBound(Arr2D(i)) <> ColIdxUBound Then
MsgBox "ArraySlice: Jagged arrays-of-arrays are not supported for column operations.", _
vbOKOnly + vbCritical, "PROGRAMMING ERROR"
Exit Function
End If
Next i
Else 'Standard 2D array
ColIdxLBound = LBound(Arr2D, 2)
ColIdxUBound = UBound(Arr2D, 2)
End If
If ColIdxLBound > SliceIdx Then 'If the specified slice-index isn't in-bounds, clip it accordingly
SliceIdx = ColIdxLBound
ElseIf ColIdxUBound < SliceIdx Then
SliceIdx = ColIdxUBound
End If
IndexFncOffset = 1 - ColIdxLBound 'The Index method assumes one-based indexing, so must adjust for
'non-one-based arrays when that is the case.
Arr1DSlice = .index(Arr2D, NA, SliceIdx + IndexFncOffset) 'Returns a degenerate 2D array of a single
'column's corresponding row values (see TECHNICAL NOTE #3, above),
'so must...
Arr1DSlice = .Transpose(Arr1DSlice) '...use Transpose to convert it to a 1D array (technically a "row"
'array in the Transpose method's context but is actually just an
'independent 1D array in this context).
'Determine whether the row-dimension base of the original 2D array is different from the base of the
'resulting sliced array (which is necessarily one-based when generated by the Index method), in order to
'fix it if necessary, below. NOTE: the column being sliced from the original 2D array is indexed by its
'row-position index values, therefore it is the 2D array's row-dimension that must be checked for possible
'adjustment of the column-sliced 1D array.
BaseOffset = 1 - RowIdxLBound
Else 'ByRow
If RowIdxLBound > SliceIdx Then 'If the specified slice-index isn't in-bounds, clip it accordingly
SliceIdx = RowIdxLBound
ElseIf RowIdxUBound < SliceIdx Then
SliceIdx = RowIdxUBound
End If
If IsArrayOfArrays Then
Arr1DSlice = Arr2D(SliceIdx) 'For array-of-arrays, just return the SliceIdx row of the 2D array
'NOTE: The Index method is not used here so there is no need to check for an array-base adjustment.
Else 'Standard 2D array
IndexFncOffset = 1 - RowIdxLBound 'The Index method assumes one-based indexing, so must adjust for
'non-one-based arrays when that is the case.
Arr1DSlice = .index(Arr2D, SliceIdx + IndexFncOffset, NA) 'Slice out the SliceIdx row
'NOTE: in the row-slice case, there is no need to transpose (from column array to row array).
'Determine whether the column-dimension base of the original 2D array is different from the base of
'the resulting sliced array (which is necessarily one-based when generated by the Index method), in
'order to fix it if necessary (below). NOTE: the row being sliced from the original 2D array is
'indexed by its column-position index values, therefore it is the 2D array's column-dimension that
'must be checked for possible adjustment of the row-sliced 1D array.
BaseOffset = 1 - LBound(Arr2D, 2) '(Is never an array-of-arrays here!)
End If
End If
If BaseOffset <> 0 Then
'The base of the original 2D array is different from the base of the resulting sliced array, so fix the
'sliced array to match the original.
ReDim Preserve Arr1DSlice(LBound(Arr1DSlice) - BaseOffset To UBound(Arr1DSlice) - BaseOffset)
End If
End With 'Application
ArraySlice = Arr1DSlice '(See the technical note at the Arr1DSlice variable's declaration)
End Function 'ArraySlice
而且，这是一个方便的测试例程，可以使用它：
Sub ArraySliceTest()
Dim ByCol As Boolean
Dim ColIdxLBound As Long
Dim ColIdxUBound As Long
Dim i As Long
Dim j As Long
Dim n As Long
Dim m As Long
Dim PadTabs As String
Dim RowIdxLBound As Long
Dim RowIdxUBound As Long
Dim Sliced As Variant
Dim SliceIdx As Long
Dim TempBuf1 As Variant
Dim TempBuf2 As String
Dim TestArr() As Variant
#Const Std2DArray = True 'For array-of-arrays, set to False
#Const JaggedArray = False 'For jagged array-of-arrays, set to True
' ByCol = True 'Uncomment for column slice
ByCol = False 'Uncomment for row slice
' SliceIdx = -1 'Uncomment slice-index value to be tested...
' SliceIdx = 0
' SliceIdx = 1
SliceIdx = 2
' SliceIdx = 3
' SliceIdx = 4
#If Std2DArray Then
' ReDim TestArr(0 To 2, 0 To 3) 'Uncomment test-array dimensions to be tested...
' ReDim TestArr(1 To 3, 1 To 4)
ReDim TestArr(-1 To 1, -1 To 2)
' ReDim TestArr(0 To 2, 1 To 4)
' ReDim TestArr(0 To 2, -1 To 2)
' ReDim TestArr(1 To 3, 0 To 3)
' ReDim TestArr(-1 To 1, 0 To 3)
RowIdxLBound = LBound(TestArr, 1)
RowIdxUBound = UBound(TestArr, 1)
ColIdxLBound = LBound(TestArr, 2)
ColIdxUBound = UBound(TestArr, 2)
'To demonstrate Variant flexibility, use integers for 2D array
For i = RowIdxLBound To RowIdxUBound
n = n + 1
m = 0 '(Re)init
TempBuf1 = vbNullString
For j = ColIdxLBound To ColIdxUBound
m = m + 1
TestArr(i, j) = n * 10 + m
Next j
Next i
#Else 'For array-of-arrays:
'To demonstrate Variant flexibility, use strings for array-of-arrays
#If Not JaggedArray Then
TestArr = Array(Array("11", "12", "13", "14"), _
Array("21", "22", "23", "24"), _
Array("31", "32", "33", "34")) 'Creates an array of arrays.
#Else
TestArr = Array(Array("11", "12", "13", "14"), _
Array("21", "22"), _
Array("31", "32", "33", "34")) 'Creates a jagged array of arrays.
#End If
'Test inconsistent col-index LBounds for all rows in an array-of-arrays (unsupported for col slice)
' Dim X As Variant
' #If JaggedArray Then
' X = Array("21", "22")
' #Else
' X = Array("21", "22", "23", "24")
' #End If
'
' ReDim Preserve X(LBound(X) - 1 To UBound(X) - 1)
' TestArr(2) = X
'Test array-of-arrays col-index LBounds other than the default (supported for row & col slice)
' Dim X As Variant
' Dim Y As Variant
' Dim Z As Variant
' X = Array("11", "12", "13", "14")
' ReDim Preserve X(LBound(X) + 1 To UBound(X) + 1)
' Y = Array("21", "22", "23", "24")
' ReDim Preserve Y(LBound(Y) + 1 To UBound(Y) + 1)
' Z = Array("31", "32", "33", "34")
' ReDim Preserve Z(LBound(Z) + 1 To UBound(Z) + 1)
' ReDim TestArr(0 To 2)
' TestArr(0) = X
' TestArr(1) = Y
' TestArr(2) = Z
RowIdxLBound = LBound(TestArr)
RowIdxUBound = UBound(TestArr)
ColIdxLBound = LBound(TestArr(RowIdxLBound)) 'Assumes consistent column-index LBounds and UBounds for
ColIdxUBound = UBound(TestArr(RowIdxLBound)) 'each row in the array-of-arrays (and is used accordingly
'below).
#End If 'Std2DArray
'Print the 2D test array
Debug.Print vbLf & "+--- " & IIf(ByCol, "Col", "Row") & " Slice ---+"
TempBuf1 = vbTab
TempBuf2 = vbTab
For j = ColIdxLBound To ColIdxUBound
TempBuf1 = TempBuf1 & Format(j, IIf(j >= 0, " 0", "#0")) & vbTab
TempBuf2 = TempBuf2 & ".." & vbTab
Next j
Debug.Print Trim$(TempBuf1)
Debug.Print Trim$(TempBuf2)
For i = RowIdxLBound To RowIdxUBound
TempBuf1 = vbNullString
#If Std2DArray Then
For j = ColIdxLBound To ColIdxUBound
TempBuf1 = TempBuf1 & TestArr(i, j) & vbTab
Next j
#Else
For j = LBound(TestArr(i)) To UBound(TestArr(i)) 'Handles jagged array-of-arrays
TempBuf1 = TempBuf1 & TestArr(i)(j) & vbTab
Next j
#End If
Debug.Print Format(i, IIf(i >= 0, " 0", "#0")) & ":" & vbTab & Trim$(TempBuf1)
Next i
'Get the slice
Sliced = ArraySlice(Arr2D:=TestArr, ByCol:=ByCol, SliceIdx:=SliceIdx)
If Not IsEmpty(Sliced) Then
'Succeeded, so print the 1D slice array
PadTabs = String(SliceIdx - LBound(Sliced), vbTab)
Debug.Print
If ByCol Then
' Debug.Print vbTab & PadTabs & Format(SliceIdx, IIf(SliceIdx >= 0, " 0", "#0"))
' Debug.Print vbTab & PadTabs & ".."
For i = LBound(Sliced) To UBound(Sliced)
Debug.Print Format(i, IIf(i >= 0, " 0", "#0")) & ": " & PadTabs & Sliced(i)
Next i
Else
TempBuf1 = Format(SliceIdx, IIf(SliceIdx >= 0, " 0", "#0")) & ":" & vbTab
For i = LBound(Sliced) To UBound(Sliced)
TempBuf1 = TempBuf1 & Sliced(i) & vbTab
Next i
Debug.Print TempBuf1
End If
Else
MsgBox "The ArraySlice function call failed"
End If
Debug.Print "+-----------------+"
End Sub
根据蒂姆·威廉姆斯的回答，我创建了一个自包含函数，该函数将切出二维数组的一个索引并返回一维数组。
Function Slice_String_Array(arr As Variant, dir As Boolean, index As Long) As Variant()
'This function recieves a two-dimensional array, slices one element of it (either a 'column' or a 'row'), and
'returns a one dimensional array with the values. Both the array passed in the arguments (arr) and the
'returned array are of type Variant.
'############################################################################################
'arr is the two-dimensional array being sliced
'"dir" is used for direction, 0 (False) is vertical (column) and 1 (True) is horizontal (column)
'"index" is the element number (column number or row number) you want returned
'############################################################################################
Set a = Application 'this is just to shorten the following lines
If dir = 0 Then 'slice a column
slice = a.Transpose(a.index(arr, 0, index))
Else 'slice a row
slice = a.Transpose(a.Transpose(a.index(arr, index, 0)))
End If
Slice_String_Array = slice
End Function