#!/usr/bin/perl

use warnings;
use strict;

my @a = qw( a1 a2 a3 );
my @b = qw( b1 b2 b3 );

my %c = ( a=>1, b=>2 );
my %d = ( c=>3, d=>4 );

sub multi_flat {
#  my ( @foo1, @foo2 ) = what should go here?
#  my ( @foo1, @foo2 ) = ( shift, shift ) ?
#  my ( @foo1, @foo2 ) = ( $_[0], $_[1] ) ?
  my @foo = @_; #this flattens the arrays into one
  print join( ", ", @foo), "\n";
}

multi_flat( @a, @b );
#prints "a1, a2, a3, b1, b2, b3"
multi_flat( %c, %d );
#prints "a, 1, b, 2, c, 3, d, 4"

sub multi_fixed_arr {
  my ( $arr1, $arr2 ) = @_;
  print "\$arr1 is ", join( ", ", @$arr1), "\n";
  print "\$arr2 is ", join( ", ", @$arr2), "\n";
}

sub multi_fixed_hash {
  my ( $hash1, $hash2 ) = @_;
  print "keys \$hash1 is ", join( ", ", keys %$hash1), "\n";
  print "keys \$hash2 is ", join( ", ", keys %$hash2), "\n";
}

multi_fixed_arr( \@a, \@b );
#prints: $foo1 is a1, a2, a3
#        $foo2 is b1, b2, b3
multi_fixed_hash( \%c, \%d );
#prints: keys $foo1 is a, b
#        keys $foo2 is c, d

sub pop_one {
  my @arr1 = @_;
  pop @arr1;
}

print join( ", ", @a), "\n";
#prints "a1, a2, a3"
pop_one( @a );
print join( ", ", @a), "\n";
#prints "a1, a2, a3"

sub pop_one_fixed {
  my $arr = shift;
  pop @$arr;
}

print join( ", ", @a), "\n";
#prints "a1, a2, a3"
pop_one_fixed( \@a );
print join( ", ", @a), "\n";
#prints "a1, a2"