#navi_header|Perl|

関数に配列またはハッシュのリファレンスを渡し、関数内で操作するサンプル

#code|perl|>
#!/usr/bin/perl

use strict;
use warnings;
use Test::More qw(no_plan);

sub foo
{
    my $h = shift;
    $h->{'val1'} = "abcdefg";
    return $h;
}
print "-------------------------\n";
print " Hash - Part I :\n";
print "-------------------------\n";

my $h1 = {val1 => 123, val2 => "faklsdjsd"};

my $ref_h = $h1;
print "hash reference(1) : [", $h1, "]\n";
is($h1->{'val1'}, 123);
is($h1->{'val2'}, "faklsdjsd");

my $h2 = foo($h1);
print 'return ref of foo($h1) : [', $h2, "]\n";
is($ref_h, $h1);
is($ref_h, $h2);
is($h1->{'val1'}, "abcdefg");
is($h2->{'val1'}, "abcdefg");

print "-------------------------\n";
print " Hash - Part II :\n";
print "-------------------------\n";

my %h1 = (val1 => 456, val2 => "lsjakfsdl");
print "hash reference(2) : [", \%h1, "]\n";
$ref_h = \%h1;
is($h1{'val1'}, 456);
is($h1{'val2'}, "lsjakfsdl");

$h2 = foo(\%h1);
print 'return ref of foo($h1) : [', $h2, "]\n";
is($ref_h, \%h1);
is($ref_h, $h2);
is($h1{'val1'}, "abcdefg");
is($h2->{'val1'}, "abcdefg");

print "-------------------------\n";
print " Arrays:\n";
print "-------------------------\n";

sub bar
{
    my $a = shift;
    push @{$a}, "abcd";
    return $a;
}

my @a1 = ( );
# is same as $a1 = [ ];
push @a1, 123;
push @a1, "hogehoge";
print "array reference : [", \@a1, "]\n";

my $ref_a = \@a1;
is(join(" ", @a1), '123 hogehoge');

my $a2 = bar(\@a1);
print 'return ref of bar(\@a1) : [', $a2, "]\n";
is($ref_a, \@a1);
is($ref_a, $a2);
is(join(" ", @a1), '123 hogehoge abcd');
is(join(" ", @$a2), '123 hogehoge abcd');

||<

実行例
#pre||>
DOS> perl hash_ref.pl
-------------------------
 Hash - Part I :
-------------------------
hash reference(1) : [HASH(0x284ef0)]
ok 1
ok 2
return ref of foo($h1) : [HASH(0x284ef0)]
ok 3
ok 4
ok 5
ok 6
-------------------------
 Hash - Part II :
-------------------------
hash reference(2) : [HASH(0x1941884)]
ok 7
ok 8
return ref of foo($h1) : [HASH(0x1941884)]
ok 9
ok 10
ok 11
ok 12
-------------------------
 Arrays:
-------------------------
array reference : [ARRAY(0x1941ac4)]
ok 13
return ref of bar(\@a1) : [ARRAY(0x1941ac4)]
ok 14
ok 15
ok 16
ok 17
1..17
||<

#navi_footer|Perl|