How to declare array with existing arrays in perl?

Question

So say I created a set of arrays like so:

my (@device, @mount, @type, @options, @dump, @pass) = ();

Then later I wanted to create an array with those arrays inside it. How would I do that? I tried to use:

my @columns = (@device, @mount, @type, @options, @dump, @pass);

and

my @columns = ([@device], [@mount], [@type], [@options], [@dump], [@pass]);

The issue seems to be that @columns remains empty. I feel like I am making a really simple syntax mistake. What have I done wrong?

Your second attempt does exactly what I thought you wanted: it produces an array that holds a copy of each of your original arrays. Please explain how that solution falls short of your produces so that we can help you further — Borodin
– Borodin, Commented Sep 22, 2012 at 21:21

Brad Gilbert · Accepted Answer · 2012-10-09 21:28:43Z

8

When you use, you just assign all values from given arrays to array @columns.
```
my @columns = (@device, @mount, @type, @options, @dump, @pass);
```

Here, you just say all array by reference, if you use Data::Dumper you can see structure of your array @columns.

use Data::Dumper;

my @columns = ([@device], [@mount], [@type], [@options], [@dump], [@pass]);
print Dumper(\@columns);

You can do it using array references. Read this tutorial: perlreftut - Mark's very short tutorial about references

my @columns = (\@device, \@mount, \@type, \@options, \@dump, \@pass);

Then use dereferencing:

my @new_device = @{ $columns[0] };

Brad Gilbert

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answered Sep 22, 2012 at 20:32

Pavel Vlasov

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use 1. not 1) to denote a list.