Perl variables scoped within a sub

Question

How would I scope to this variable depending on a conditional of papertype?

I have tried it several ways and I am getting errors and I am befuddled.

sub paperdisplay_getPaperLink {
    my ( $self, $args ) = @_;
    my $paper    = $args->{paper};
    my $linktext = $args->{linktext};
    my $session  = $args->{session};

    my $query    = $self->request;
    my $password = $query->param('password');

    if ( $paper->{Type} eq 'Break' ) {
        my $url = $something;
    } else {
        my $url = $somethingelse;
    }

    my $link = qq(<a title="$linktext" target="other" href="$url">$linktext</a>);

    return $link;
}

amphetamachine · Accepted Answer · 2014-08-28 15:59:50Z

6

You have to declare it in the block you want to use it in. If you declare it inside the if or else block, it'll only exist there. The variable would be destroyed when the block ends.

my $url;
if ($paper->{Type} eq 'Break') {
    $url = $something
} else {
    $url = $somethingelse
}
# $url still exists down here

edited Aug 28, 2014 at 15:59

answered Aug 28, 2014 at 15:49

amphetamachine

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3 Comments

Sobrique Over a year ago

Or you could do my $url = $somethingelse; outside the loop and change it if that condition is true.

amphetamachine Over a year ago

@Sobrique Why contradict yourself and make the computer do extra work?

Sobrique Over a year ago

Because the computer doesn't deserve to have an easy time of it. It's been naughty and must be punished. But honestly, it depends on scenario - if usually it'll be one state, but occasionally it will be different, setting the 'default state' and switching it on hitting the exception I feel improves code clarity.

Miller · Accepted Answer · 2014-08-28 22:06:45Z

4

Use the Conditional Operator to initialize a variable without the need for an if block:

my $url = $paper->{Type} eq 'Break'
    ? $something
    : $somethingelse;

edited Aug 28, 2014 at 22:06

Miller

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answered Aug 28, 2014 at 15:58

Ron Bergin

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