Character Classes

A character class describes which characters may appear at a position.

character_classes.pl

use strict;
use warnings;

my $name = ;
my $valid = $name =~ /^[A-Za-z0-9_]+$/;
my $status = $valid ? "valid" : "invalid";

print "name=$name\n";
print "status=$status\n";

use strict;
use warnings;

my $name = ;
my $valid = $name =~ /^[A-Za-z0-9_]+$/;
my $status = $valid ? "valid" : "invalid";

print "name=$name\n";
print "status=$status\n";

use strict;
use warnings;

my $name = ;
my $valid = $name =~ /^[A-Za-z0-9_]+$/;
my $status = $valid ? "valid" : "invalid";

print "name=$name\n";
print "status=$status\n";

character class A character class like `[A-Za-z0-9_]` matches one allowed character from a set.