Is the regular expression [a-Z] valid and if yes then is it the same as [a-zA-Z]?

Question

Is the regular expression [a-Z] valid and if yes then is it the same as [a-zA-Z]? Please note that in [a-Z] the a is lowercase and the Z is uppercase.

E

Answer 1

You could always try it:

 print "ok" if "monkey" =~ /[a-Z]/;

Perl says

Invalid [] range "a-Z" in regex; marked by <-- HERE in m/[a-Z <-- HERE ]/ at a-z.pl line 4.