Error trying to loop through array of hashes in Perl

Question

This has been asked before a couple of times, but none of those answers seem to work for my situation.

My code:

open(FILE, "<", $fileb) or die "File not openable: $!";
while (<FILE>) {
    $filebmeta[$line] = (data => $_, match => -1);
    $line++;
}
close(FILE);
$line = 0;


for my $hashref (@filebmeta) {
     print "$hashref->{data}\n";
}

when I run this code it spits out: 'Can't use string ("-1") as a HASH ref while "strict refs" in use at ./partc.pl line 152.'

Any idea why this is happening? I don't seem to be able to dereference the hash properly in the loop.

Instead of `$line` use `$.`. Also, `use warnings` will solve this. — Chris Lutz, Jul 15 '11 at 05:20
Or use `push` instead of assigning to a numbered array element with `$line` or `$.`. — evil otto, Jul 15 '11 at 05:23

score 7 · Accepted Answer · answered Jul 15 '11 at 05:20

The elements of the array need to be hashrefs, so your assigment statement needs to use curly brackets:

$filebmeta[$line] = {data => $_, match => -1};

You code is assigning a list to the array, so it just gets the last element in the list which is the -1. Thus your error message.

score 4 · Answer 2 · answered Jul 15 '11 at 05:20

4

Your expression (data => $_, match => -1) does not create a hashref, it creates a list. You probably meant {data => $_, match => -1}

answered Jul 15 '11 at 05:20

evil otto

10,348
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score -1 · Answer 3 · answered Jul 15 '11 at 05:26

-1

You mean besides all the undefined variables in your code? Read perlreftut and pay attention to the syntax.

answered Jul 15 '11 at 05:26

7stud

117
4

They're all declared, just out of the scope of my code snipit. – Ash Jul 15 '11 at 05:32

Error trying to loop through array of hashes in Perl

3 Answers3