We have regular expressions, and they have metacharacters and character classes.

if ( $char =~ /\d/ ) {
    print "It's a digit.\n";
}
if ( $char =~ /\w/ ) {
    print "It's a word-like character.\n";
}
if ( $char =~ /[a-zA-Z]/ ) {
    print "It's an asciibetical alpha character.\n";
}
if ( $char =~ /[[:alpha:]]/ ) {
   print "It's an alpha character.\n";
}
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...just to name a few possibilities. See perlre for details.