CODEWITHSUNDEEP
perl
ado
ado

Reputation: 1471

How should I assigned the same value to two different keys in this Perl hash?

When I have 2 data structures meaning the same thing, ex:

$c->req->cookies->{app1} = $c->req->cookies->{general};
$c->req->cookies->{app2} = $c->req->cookies->{general};

Can I write:

( $c->req->cookies->{app1}, $c->req->cookies->{app2} ) = $c->req->cookies->{general};

?

Also, Can I write:

   $c->req->cookies->{app1} =  $c->req->cookies->{app2 } = $c->req->cookies->{general};

?

Upvotes: 2

Views: 54

Answers (2)

choroba
choroba

Reputation: 241858

The second form is possible and some people use it frequently

$x = $y = $z;

The first form does not do what you need. It only assings the value to the first variable.

($x, $y) = $z;

You need two member list on the right hand side as well:

($x, $y) = ($z) x 2;

Update: In your case, you can use the x operator only if the methods involved return the same values for both invocations, otherwise, you can use

($x, $y) = map $obj->method, 1, 2;

Upvotes: 7

Sinan Ünür
Sinan Ünür

Reputation: 118128

As usual, there are many ways to do it. For example, you could also use a hash slice:

@{ $c->req->cookies }{qw( app1 app2 )}

But, I would recommend a lack of originality:

my $cookies = $c->req->cookies;
my $general_cookie = $cookies->{general};
$cookies->{$_} = $general_cookie for qw(app1 app2);

which makes the code more readable, doesn't create new data structures, and reduces complex dereferencing as much as possible.

Upvotes: 4

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