nikolay has asked for the wisdom of the Perl Monks concerning the following question:

In the following code i want to dereference the array's element $a[0]. 
my $q='qwer';
my @a=( \$q );

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How to do that? Using additional variable i do it so 
my $a=$a[0];
print "$a\n";

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How to do the same w/o additional variable. Reading PERL documentations did not reveal me the secret of syntax of the case. Thanks for advice.

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Re: How to dereference array of ref.s?
by Discipulus (Canon) on May 20, 2018 at 14:46 UTC
    Hello nikolay

    you can dereference using braces and prepending the right sigyl;  print ${ $a[0] }

    Standard doc is perlref

    Your array element is just a plain scalar and you must learn just how to derefence a sclar. Infact is the same of:  my $ref = \'qwerty'; print ${ $ref }

    If no confusion is possible, as in my second example, you can dereference without braces like in  print $$ref or using postfix dereference  use feature 'postderef'; my $ref = \'qwerty'; print $ref->$* but see the above docs for versions of perl that have this feature enable or usable.

    L*

    There are no rules, there are no thumbs..
    Reinvent the wheel, then learn The Wheel; may be one day you reinvent one of THE WHEELS.
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      versions of perl that have this feature enable or usable

      The Postfix Dereference Syntax is enabled by default in Perl 5.24 and above. E.g. on v5.26:

      $ perl -wMstrict -e' my $q="qwer"; my @a=(\$q); print $a[0]->$*,"\n";'
qwer

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      However, if you want it to interpolate in strings, you do need to enable the postderef_qq feature, for example via the v5.24 feature bundle ("use 5.024;"):

      $ perl -wM5.024 -e' my $q="qwer"; my @a=(\$q); print "$a[0]->$*\n";'
qwer

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      Thank you! Awesome!
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Re: How to dereference array of ref.s?
by Arunbear (Prior) on May 20, 2018 at 14:49 UTC 
    % perl -dee

Loading DB routines from perl5db.pl version 1.49_05
Editor support available.

Enter h or 'h h' for help, or 'man perldebug' for more help.

main::(-e:1):    e
  DB<1> $q='qwer'

  DB<2> @a=( \$q )

  DB<3> x @a
0  SCALAR(0x1158960)
   -> 'qwer'
  DB<4> p ${$a[0]}
qwer

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    So essentially 
    print ${ $scalar_ref };

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    See also References quick reference
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      Great!
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Re: How to dereference array of ref.s?
by johngg (Canon) on May 20, 2018 at 14:53 UTC

    This is also useful.

    Cheers,

    JohnGG

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