Subscript Out Of range when selecting an array I've created - arrays

Question

I'm trying to create a single PDF file containing a sheet for each tab which I have listed from cell J2 in my Control sheet but I keep getting a Subscript Out Of Range error.
When I record the action I see that it creates an array of sheet names which it then selects to export, so I have a For loop which goes through the list and creates an array which adds to itself until it reaches the end of the list - the aim being to create one long string which I then select as an array.
All appears to be good (the variable PDFArray displays a string of the tab names in what appears to be the correct format) but when I get to the line 'Worksheets(Array(PDFarray)).Select' then I get the error. I've made sure the sheet names contain no undesirable characters or spaces but still no joy. Any help would be very much appreciated. Thank you
Sub B_PDFs()
Dim PDFarray As String, PDFName as String, sht As String
Sheets("Control").Select
PLFile = ActiveWorkbook.Name
PDFLoc = Application.ActiveWorkbook.Path & "\"
PDFName = Range("A20")
PDFSheetCount = Range("J1").Offset(Rows.Count - 1, 0).End(xlUp).Row
'Loop through column J and create a string with each tab name to be exported
For x = 2 To PDFSheetCount Step 1
If x = PDFSheetCount Then
sht = """ " & "" & Cells(x, 10) & """ "
Else
sht = """" & "" & Cells(x, 10) & """" & ", "
End If
PDFarray = PDFarray & sht
Next x
'Create PDF from the array above
Worksheets(Array(PDFarray)).Select - this is where I get the error Subscript Out Of Range
Selection.ExportAsFixedFormat Type:=xlTypePDF, Filename:=PFDLoc & PDFName, Quality:= _
xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas:=False,
OpenAfterPublish:=False
Workbooks(PLFile).Activate
End Sub

Answer 1

I don't understand why MS makes NOT requiring variable declaration the default. Select Tools/Options/Editor and check Require Variable Declaration. This will place Option Explicit at the start of any new module. To correct this module, enter it manually at the beginning.
Doing so would have enabled you to find and correct a typo in your code.
You should also be avoiding Select, Selection and Activate. They rarely serve any purpose at all, and can cause multiple problems because they lull into avoiding explicit declarations of which workbook, worksheet, etc. you need. See How to avoid using Select in Excel VBA
However in using the ExportAsFixedFormat method to export selected worksheets, it seems Selection and ActiveSheet are required for it to work.
Array(str_variable) returns an array with a single entry that contains the entire string variable. It does not interpret the string variable so as to split it into separate elements.
So, rewriting your code somewhat (I will leave it to you to clean up the PDF document):
Option Explicit
Sub B_PDFs()
Dim PDFarray As Variant, PDFName As String, PLFile As String, PDFLoc As String
Dim wsControl As Worksheet
Dim WB As Workbook
'Consider wheter you want to use ThisWorkbook or a specific workbook
Set WB = ThisWorkbook
With WB
Set wsControl = .Worksheets("Control")
PLFile = .Name
PDFLoc = .Path & "\"
End With
With wsControl
PDFName = .Range("A20")
'create PDFarray
'This will be a 1-based 2D array starting at J1
'If you need to start at J2, alter the initial cell
PDFarray = .Range(.Cells(1, 10), .Cells(.Rows.Count, 10).End(xlUp))
End With
'convert to a 1D array
PDFarray = WorksheetFunction.Transpose(PDFarray)
'Note the use of `Select` and `ActiveSheet` when using this `ExportAsFixedFormat` method
Worksheets(PDFarray).Select
'Create PDF from the array above
ActiveSheet.ExportAsFixedFormat Type:=xlTypePDF, Filename:=PDFLoc & PDFName, Quality:= _
xlQualityStandard, IncludeDocProperties:=True, IgnorePrintAreas:=False, OpenAfterPublish:=False
End Sub

Answer 2

What #RonRosenfeld has suggested is correct about select and selection. The expression you are building is string whereas, Excel expects it to be real array.
So in principle an approach like below shall work for you which will create an array for processing and can be used as you want to utilise.
Dim shtNames As Variant
Dim pdfArray
shtNames = Range("J2:J" & Range("J1").Offset(Rows.Count - 1, 0).End(xlUp).Row).Value
pdfArray = Application.Transpose(shtNames)