Using the contents of a variable to reference an element in an array in Perl

Question

Is it possible to use the contents of a variable to reference an element in an array in Perl?

I am creating a variable (see $printelement below) that contains the values "$element[0]", "$element[1]", "$element[2]" and so on.

$counter = 0;
$counter2 = 1; 

$elementlabel = "element";
$opensquarebracket = "[";
$closesquarebracket = "]";

@element = qw(Fast Times at RidgemontHigh); 

print "Array contents:\n\n";

print "This is element[0] : $element[0]\n";
print "This is element[1] : $element[1]\n";
print "This is element[2] : $element[2]\n";
print "This is element[3] : $element[3]\n\n";

while ($counter2 <= 4)
{

   $jk = "\$$elementlabel$opensquarebracket$counter$closesquarebracket";

   $printelement = $jk;
   
   print "This is  element[$counter] : $element[$counter]\n";

   print "This is $printelement : $element[$counter]\n";
   
   print "This is $printelement : $printelement\n\n";

   $counter++;
   $counter2++;
   
}

Instead of printing the contents of the array element, the contents of the variable are printing (see output below):

Array contents:

This is element[0] : Fast
This is element[1] : Times
This is element[2] : at
This is element[3] : RidgemontHigh

This is  element[0] : Fast
This is $element[0] : Fast
This is $element[0] : $element[0]

This is  element[1] : Times
This is $element[1] : Times
This is $element[1] : $element[1]

This is  element[2] : at
This is $element[2] : at
This is $element[2] : $element[2]

This is  element[3] : RidgemontHigh
This is $element[3] : RidgemontHigh
This is $element[3] : $element[3]

Thanks in advance. Your help is greatly appreciated.

Tip: for my $counter (0..$#elements) { ... } would be far better than $counter = 0; $counter2 = 1; while ($counter2 <= 4) { ... $counter++; $counter2++; } — ikegami
– ikegami, Commented Jul 23, 2020 at 5:58

ikegami · Accepted Answer · 2020-07-23 05:48:49Z

2

To execute a string that consists of Perl code, you can use eval EXPR.

my $x = eval($printelement);
die $@ if $@;

answered Jul 23, 2020 at 5:48

ikegami

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