Perl, dereference array of references

Question

In the following Perl code, I would expect to be referencing an array reference inside an array

#!/usr/bin/perl

use strict;
use warnings;

my @a=([1,2],[3,4]);

my @b = @$a[0];

print $b[0];

However it doesn't seem to work. I would expect it to output 1.

@a is an array of references

@b is $a[1] dereferenced (I think)

So what's the problem?

mob · Accepted Answer · 2010-06-03 20:41:00Z

11

This stuff is tricky.

@$a[0] is parsed as (@$a)[0], dereferencing the (undefined) scalar $a

You wanted to say @{$a[0]}.

answered Jun 3, 2010 at 20:41

mob

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2 Comments

there's so many quirks in Perl I'm still getting used to. thanks for your help

When in doubt, just add more braces :D