Var for just Letters...

[2710]

hi,

what variable should I use for JUST letters, just the 26 letters of the alphabet. No symbols, no numbers etc. I thought of using char, but that includes symbols. Or is there any other way to make an error come up if a letter is not inputted?

I dont really want to do:

If (Letter <> a) and (Letter <> b) and (Letter <> c) .... (Letter <> z) and (Letter <> A) and (Letter <> B) and (Letter <> C) .... (Letter <> Z)

then writeln ('Error');

Thanks

[BlaineSch]

Try using regular expressions. Either filter out all a-z characters and see if the length is greater than 0 - or do a match or filter out all but a-z etc depending on what you want.

Regular-Expressions.info - Regex Tutorial, Examples and Reference - Regexp Patterns

[WingedPanther]

Virtually all languages (including Pascal descendants) use ASCII or Unicode for storing character information. If you want a subset of those characters, such as the upper/lowercase letters in the English alphabet, you need to create a filter. If you know your encoding, you can often do something like:

if not  (((letter >= 'a') and (letter <='z')) or ((letter >= 'A') and (letter <='Z'))) then
writeln('Error');

[2710]

Thanks for that Winged Panther Forgot you can use > and < for letters. Thanks to the other guy too, but I didn't really understand lol.

[BlaineSch]

Even if you don't use my method learning regular expressions will GREATLY help your programming knowledge in the future.

Good luck!

[Rustix666]

For the English alphabet use:

Letter:=UpperCase(Letter);   //'a'=>'A'
if (Ord(Letter)<64) or (Ord(Letter)>90) then
showmessage('Error.');

[Tiago2]

Try this

Var 
  Letter: Char;

  if Not (Letter in ['a'..'z','A'..'Z']) then
    ShowMessage('Error.')

This should let you filter out any charecters that are not in the alphabet