Различия между Perl 5 и Perl 6

Differences between Perl 5 and Perl 6

=head1 NAME

Perl6::Perl5::Differences -- Differences between Perl 5 and Perl 6

=head1 DESCRIPTION

This document is intended to be used by Perl 5 programmers who are new to Perl
6 and just want a quick overview of the main differences. More detail on
everything can be found in the language reference, which have been linked to
throughout.

This list is currently known to be incomplete.

=cut

# S02

=head1 Bits and Pieces

=head2 Sigils

Where you used to say:

my @fruits = ("apple", "pear", "banana");
print $fruit[0], "\n";

You would now say:

my @fruits = "apple", "pear", "banana";
say @fruit[0];

Or even use the C<< <> >> operator, which replaces C<qw()>:

my @fruits = <apple pear banana>;

Note that the sigil for fetching a single element has changed from C<$>
to C<@>; perhaps a better way to think of it is that the sigil of a
variable is now a part of its name, so it never changes in subscripting.

The same applies to hashes:

say "There are %days{'February'} days in February";

Again, there is a shorter form:

say "There are %days<February> days in February";

For details, see L<S02/"Names and Variables">.

=head2 Global variables have a twigil

Yes, a twigil. It's the second character in the variable name. For globals,
it's a C<*>

Was: $ENV{FOO}
Now: %*ENV<FOO>

For details, see L<S02/"Names and Variables">.

=head2 New ways of referring to array and hash elements

Number of elements in an array:

Was: $#array+1 or scalar(@array)
Now: @array.elems

Index of last element in an array:

Was: $#array
Now: @array.end

Therefore, last element in an array:

Was: $array[$#array]
Now: @array[@array.end]
@array[*-1] # beware of the "whatever"-star

For details, see L<S02/"Built-In Data Types">

=head2 The double-underscore keywords are gone

Old New
--- ---
__LINE__ $?LINE
__FILE__ $?FILE
__PACKAGE__ $?PACKAGE
__END__ =begin END
__DATA__ =begin DATA