Removing Cells from an Excel Range

[Guest]

Hi All:

For an Excel macro I’d like to know how to remove items (in this case,
individual cells) from a range of cells – but without deleting the cells from
the worksheet. What the macro does is basically to take two lists of unique
identifiers and to look for the IDs of list 1 among the IDs of list 2. This
is done by looping through the range of cells that make up list 1, and
searching for each of the IDs of list 1 in the range of cells that make up
list 2. If a match is found the macro does some more work, but the question
I have relates to the part that compares the lists only. In this part of the
macro I’d like to take advantage of the efficient built-in Find method.

So basically:

For Each cell in Range1
Set r = Range2.Cells.Find(cell.Value)
If Not r Is Nothing Then
' do some work
End If
Next

The problem I have is that even though the IDs are unique, the macro will
continue to search through all the IDs of list 2 (Range2), even those that
have been matched already. To me the solution would seem to be to remove
matched cells from Range2 so that Find doesn’t search them again. However, I
did not find a way of doing that. The Delete method is not useful because it
removes the cells from the worksheet, which I don’t want to do. What I do
want to do is change the selected range of cells – but how? Especially in a
way that doesn’t waste more time redefining Range2 than there is saved by
searching a shrinking list?

I’d appreciate to get your help and input on this problem, and apologize if
I failed to find the answer in existing posts. Many thanks already in
advance,

Anton

 

[Don Guillett]

Have a look in vba help for find or findnext

 

[Guest]

Sorry, but I don't see the light. Perhaps I should add that the IDs are not
sorted in either list, so that guarding against wrap-around doesn't help.

Anton

 

[Don Guillett]

FindNext Method
See Also Applies To Example Specifics
Continues a search that was begun with the Find method. Finds the next cell
that matches those same conditions and returns a Range object that
represents that cell. Doesn't affect the selection or the active cell.

expression.FindNext(After)

expression Required. An expression that returns a Range object.

After Optional Variant. The cell after which you want to search. This
corresponds to the position of the active cell when a search is done from
the user interface. Note that After must be a single cell in the range.
Remember that the search begins after this cell; the specified cell isn't
searched until the method wraps back around to this cell. If this argument
isn't specified, the search starts after the cell in the upper-left corner
of the range.

Remarks
When the search reaches the end of the specified search range, it wraps
around to the beginning of the range. To stop a search when this wraparound
occurs, save the address of the first found cell, and then test each
successive found-cell address against this saved address.

Example
This example finds all cells in the range A1:A500 that contain the value 2
and changes their values to 5.

With Worksheets(1).Range("a1:a500")
Set c = .Find(2, lookin:=xlValues)
If Not c Is Nothing Then
firstAddress = c.Address
Do
c.Value = 5
Set c = .FindNext(c)
Loop While Not c Is Nothing And c.Address <> firstAddress
End If
End With

 

[Guest]

Sorry, but I just don't see the solution to my problem. Are you suggesting
that I save the addresses of the cells with matching content and to check in
subsequent rounds whether a cell address is among the saved addresses or not?
And then to compare contents only if this is a "new" cell address? That
could be done of course but I doubt that it would be faster than re-checking
all cell contents.

Maybe I should re-state the problem:
- list 1 contains single occurrences of some unique IDs
- list 2 also contains single occurrences of some unique IDs
- when looping through list 1 to compare the IDs to list 2, all of list 2 is
searched at each round when already found matches could be eliminated

Anton