##
$A[ord $_]++ for split '', $str;
if (grep $_, @A[map ord, a..z,A..Z]) {
...
}
##
##
$H{$_}++ for split '', $str;
if (grep $H{$_}, a..z, A..Z) {
...
}
##
##
$A[ord $_]++ for split '', $str;
if (grep $A[ord $_], a..z, A..Z) {
...
}
##
##
use POSIX;
if ( grep { isalpha $_ } split '', $str ) {
...
}