VBA Loop across one row to find a value that contains a cell and delete columns before that column - vba

Question

I need to check each cell in row 7 starting from C7 (C7, D7, E7, etc) and find a cell with a string value that contains a certain date (for example, "9/30/2017" in string "6/30/2017 to 9/30/2017") and delete ALL columns from column C to whatever column that the cell is in. How would I do this with VBA code? I am new to VBA and have tried everything that I could find. Thankful for any suggestions
My code:
Sub DeleteUnnecessaryColumns(specifiedWorksheet)
Dim lastCol As Long
lastCol = Cells.Find(What:="*", After:=[C1], SearchOrder:=xlByColumns, SearchDirection:=xlPrevious).Column
For i = 1 To lastCol
If InStr(Cells(7, 0), specifiedDate, vbTextCompare) = 0 Then
Columns(i).Delete
End If
Next i
End Sub

Answer 1

A few changes:
Use a With block to explicitly target the specified worksheet
Add a . before the Cells collection to explicitly link to the specified worksheet (through the With block)
Start the loop with the correct column index for Column C = 3 (For i = 3 ...)
You missed the first argument to the InStr function: starting character (1 was assumed) MSDN
The second argument for InStr wasn't set to the i variable. This will now cycle through the values in each column
The loop would not stop once it found the search text. So I added an Else clause that exits the For loop once specifiedDate is found, preventing the script from deleting columns to the right of the target column.
specifiedDate was never passed to the Sub or declared so I added it as a parameter. You can also declare and set it within this procedure. If it's declared as a public variable, then delete the parameter.
The .Find method is only available to a range object, so I used a method available to cells instead
After a column is deleted, the indices for the remaining columns are reduced by one so the same must be done to the variables controlling the loop
It should now properly delete a column if the search text is not found in row 7 and will stop executing once the first match is found, leaving the remaining columns intact.
Sub DeleteUnnecessaryColumns(specifiedWorksheet, specifiedDate)
Dim lastCol As Long
With specifiedWorksheet
lastCol = .Cells(7, .Columns.Count).End(xlToLeft).Column
For i = 3 To lastCol
If InStr(1, .Cells(7, i), specifiedDate, vbTextCompare) = 0 Then
.Columns(i).Delete
i = i - 1
lastCol = lastCol - 1
Else
Exit For
End If
Next i
End With
End Sub

Answer 2

Something like... You need to call it from somewhere else, using syntax like DeleteUnnecessaryColumns "Sheet1", "9/30/2017"
Sub DeleteUnnecessaryColumns(specifiedWorksheet as worksheet, SpecifiedDate as string)
dim r as range ' set up a range for row 7, columns C to the end
set r = specifiedWorksheet.rows(7)
set r = r.resize(Columnsize:= r.columns.count - 2)
set r = r.offset(0,2)
Dim lastCol As Long, i as long
for i = 1 to r.columns.count 'loop through the cells in the r range
if instr(string:=r.cells(i), substring:= SpecifiedDate) > 0 then
lastcol = i 'this ends the loop and sets the value for lastcol
end if
next
SpecifiedWorksheet.range(cells(1, 3), cells(1, lastcol - 1).entirecolumn.delete
End Sub