perl can't use string as an array ref

Question

I have 4 apps. let's call them: App1, App2, App3 and App4.

for each of these apps I have an array: for example:

my @App1_links = (...some data...);
my @App2_links = (...some data...);
my @App3_links = (...some data...);
my @App4_links = (...some data...);

Now I have a loop in my code that goes thru these 4 apps and I intend to do something like this:

my $link_name = $app_name . "_links";
    where $app_name will be App1, App2 etc...

and then use it as : @$link_name

Now this code does what I intend to do when I don't use: use strict but not otherwise

The error is: Can't use string ("App1_links") as an ARRAY ref while "strict refs" in use at code.pm line 123.

How can I achieve this functionality using use strict.

Please help.

It would be nice, if you provided more meaningful snippet. Do you have arrays with these names and are trying to access them? — user4035, Jul 19 '12 at 18:38
I thought I gave enough information. Please tell me what is ambiguous in the post and I can fix it. The names can be anything but the idea is what I want to express and get the point across to you. — soothsayer, Jul 19 '12 at 18:48

score 4 · Accepted Answer · answered Jul 19 '12 at 18:41

4

You are using $link_name as a symbolic reference which is not allowed under use strict 'refs'.
Try using a hash instead, e.g.

my %map = (
    App1 => \@App1_links,
    ...
);
my $link_name = $map{$app_name};

answered Jul 19 '12 at 18:41

Eugene Yarmash

142,882
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Thanks for the solution. Let me try this out. – soothsayer Jul 19 '12 at 18:53

score 4 · Answer 2 · edited May 23 '17 at 12:12

4

As I say elsewhere, when you find yourself adding an integer suffix to variable names, think "I should have used an array".

my @AppLinks = (
    \@App1_links,
    \@App2_links,
    \@App3_links,
    # ...
);

for my $app ( @AppLinks ) {
    for my $link ( @$app ) {
        # loop over links for each app
    }
}

or

for my $i ( 0 .. $#AppLinks ) {
    printf "App%d_links\n", $i + 1;
    for my $link ( @{ $AppLinks[$i] } ) {
        # loop over links for each app
    }
}

edited May 23 '17 at 12:12

Community

1
1

answered Jul 19 '12 at 18:47

Sinan Ünür

116,958
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196
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My loop is going through the 4 apps, hence my need to concatenate and get the link_name. I would have to change a lot of code to loop through the array. Any other ideas? – soothsayer Jul 19 '12 at 18:51
I do not see any valid reason to use `no strict 'refs';` here. Doing that would "solve" your problem for some value of "solve". The code above loops over all the links for all the apps. – Sinan Ünür Jul 19 '12 at 18:54

perl can't use string as an array ref

2 Answers2