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+---- Thread: Testing against multiple elements at a time without select case (/showthread.php?tid=3619)
Testing against multiple elements at a time without select case - CMR - 04-16-2025
Select Case lets you test against things like this: Case 1, 2, 3, 4, 5 Is there a way to use this kind of expression list with 'If'? I'm trying to make a little program that builds sprite sheets from a list of image files, and I'm testing to see if the file name extension matches an image files. Here's the Sub I'm working on. It just builds a list of file names from the files listed in a text file.
Code: (Select All)
Sub LoadFromTxt( txt_file$, names_list$() )
''load a list of file names from a txt file
Dim fp& : fp& = Freefile
Dim tmp$
Dim count& : count& = 1
Open txt_file$, For Input as fp&
While Not EOF(fp&)
Line Input fp&, tmp$
tmp$ = LTrim$(RTrim$(tmp$))
If tmp$ <> "" Then
''test for image suffix .*
Select Case Mid$(tmp$, Len(tmp$) - 4, 4)
Case ".png",".bmp",".jpg",".tga", _
".psd",".gif",".hdr",".pic",".pnm", _
".pcx",".svg",".ico",".cur",".qoi"
names_list$(count&) = tmp$
count& = count& + 1
Case Else
Print "Unknown file type " + tmp$
End Select
End If
Wend
Close fp&
End Sub
I just feel like it would look better with a couple of 'If' statements instead, and was wondering if you could use expression lists with If the way you could Select Case.
RE: Testing against multiple elements at a time without select case - SMcNeill - 04-16-2025
Something similar to this?
Code: (Select All)
Sub LoadFromTxt (txt_file$, names_list$())
''load a list of file names from a txt file
Dim fp&: fp& = FreeFile
Dim tmp$
Dim count&
Open txt_file$ For Input As fp&
While Not EOF(fp&)
Line Input #fp&, tmp$
tmp$ = Right$(_Trim$(tmp$), 4)
If Len(tmp$) = 4 Then
If InStr(".png.bmp.jpg.tga.psd.gif.hdr.pic.pnm.pcx.svg.ico.cur.qoi", tmp$) Then
count& = count& + 1
names_list$(count&) = tmp$
Else
Print "Unknown file type " + tmp$
End If
End If
Wend
Close #fp&
End Sub
RE: Testing against multiple elements at a time without select case - CMR - 04-16-2025
That's great. I didn't even think of using InStr. Thanks.
RE: Testing against multiple elements at a time without select case - eoredson - 04-16-2025
You could also try:
Code: (Select All)
Sub LoadFromTxt (txt_file$, names_list$())
' load a list of file names from a txt file
Dim fp&: fp& = FreeFile
Dim tmp$
Dim count&: count& = 1
Open txt_file$ For Input As fp&
While Not EOF(fp&)
Input fp&, tmp$
tmp$ = LTrim$(RTrim$(tmp$))
If tmp$ <> "" Then
' test for image suffix .*
Restore
Do
Read Tst$
If Tst$ = ".eod" Then Exit Do
If Mid$(tmp$, Len(tmp$) - 4, 4) = Tst$ Then
names_list$(count&) = tmp$
count& = count& + 1
End If
Loop
End If
Wend
Close fp&
End Sub
Data ".png",".bmp",".jpg",".tga",".psd",".gif",".hdr",".pic",".pnm",".pcx",".svg",".ico",".cur",".qoi",".eod"RE: Testing against multiple elements at a time without select case - CMR - 04-17-2025
That's cool too. Someday I need to do a deep dive into all the stuff you can do with DATA and READ statements. Here's what I ultimately decided on. It's very similar to SMcNeill's. I decided to move the list count outside, so I can track my position in the array regardless of how many times I call this function or others. I made the extension string its own thing also just to keep my line widths down. Now I just need to test the thing and see if it works.
Code: (Select All)
Sub LoadFromTxt( txt_file$, names_list$(), list_count& )
''load a list of image file names from a txt file
Dim fp& : fp& = Freefile
Dim tmp$
Dim f_ext$
f_ext$ = ".png.bmp.jpg.tga.psd.gif.hdr.pic.pnm.pcx.svg.ico.cur.qoi"
Open txt_file$, For Input as fp&
While Not EOF(fp&)
Line Input fp&, tmp$
tmp$ = _Trim$(tmp$)
If tmp$ <> "" Then
''test for image suffix .*
If InStr(f_ext$, Right$(tmp$, 4)) Then
list_count& = list_count& + 1
names_list$(list_count&) = tmp$
Else
Print "Unknown file type " + tmp$
End If
End If
Wend
Close fp&
End Sub ''LoadFromTxt