>> Test for alpha character

[Jonathan]

Hi using Access 2003, is there a way to check whether a string contains alpha
characters?

Here is my code that checks string for at least 1 alpha character

For myLoop = 1 To Len(myString)
myChr = Mid(myString, myLoop, 1)
If myChr > Chr(64) And myChr < Chr(91) Or _
myChr > Chr(96) And myChr < Chr(123) Then
msg = vbNullString
Exit For
End If
Next myLoop

I guess that I'm looking for a function that returns the ascii number of
myChr.

Any ideas or suggestions appreciated

Many thanks,
Jonathan

 

[Robert Morley]

If you need the ASCII value for the code, then the way you're doing it is on
the right track (though I'll tweak it a bit for the ASCII value below). If
all you need to do is check if there IS an alpha character, then I'd suggest
you use:

IsAlpha = myString Like "*[a-z]*" 'if you know Option Text is in effect
or IsAlpha = myString Like "*[A-Za-z]*" 'if you don't.

But if you specifically need the ASCII value, here's the code you want:

For myLoop = 1 To Len(myString)
myChr = Asc(Mid(myString, myLoop, 1)) 'Dim myChr As Long instead
If myChr > 64 And myChr < 91 Or _
myChr > 96 And myChr < 123 Then
msg = vbNullString
Exit For
End If
Next myLoop

You may also get better performance out of a Select Case in this intance,
I'm not sure...give it a try if performance is importance:

For myLoop = 1 To Len(myString)
myChr = Asc(Mid(myString, myLoop, 1)) 'Dim myChr As Long instead
Select Case myChr
Case 64 To 91, 96 To 123
msg = vbNullString
Exit For
End Select
Next myLoop

I'm not sure if you can use an Exit For from within a Select Case statement,
though...I never use the things. If not, post back and I'll restructure
your loop for you to use Do Until or Do While.



Rob

 

[Jonathan]

Really great response to my question. Many thanks

Jonathan

If you need the ASCII value for the code, then the way you're doing it is on
the right track (though I'll tweak it a bit for the ASCII value below). If
all you need to do is check if there IS an alpha character, then I'd suggest
you use:

IsAlpha = myString Like "*[a-z]*" 'if you know Option Text is in effect
or IsAlpha = myString Like "*[A-Za-z]*" 'if you don't.

But if you specifically need the ASCII value, here's the code you want:

For myLoop = 1 To Len(myString)
myChr = Asc(Mid(myString, myLoop, 1)) 'Dim myChr As Long instead
If myChr > 64 And myChr < 91 Or _
myChr > 96 And myChr < 123 Then
msg = vbNullString
Exit For
End If
Next myLoop

You may also get better performance out of a Select Case in this intance,
I'm not sure...give it a try if performance is importance:

For myLoop = 1 To Len(myString)
myChr = Asc(Mid(myString, myLoop, 1)) 'Dim myChr As Long instead
Select Case myChr
Case 64 To 91, 96 To 123
msg = vbNullString
Exit For
End Select
Next myLoop

I'm not sure if you can use an Exit For from within a Select Case statement,
though...I never use the things. If not, post back and I'll restructure
your loop for you to use Do Until or Do While.



Rob

Hi using Access 2003, is there a way to check whether a string contains alpha
characters?

Here is my code that checks string for at least 1 alpha character

For myLoop = 1 To Len(myString)
myChr = Mid(myString, myLoop, 1)
If myChr > Chr(64) And myChr < Chr(91) Or _
myChr > Chr(96) And myChr < Chr(123) Then
msg = vbNullString
Exit For
End If
Next myLoop

I guess that I'm looking for a function that returns the ascii number of
myChr.

Any ideas or suggestions appreciated

Many thanks,
Jonathan