Add quotes to all elements inside of an array in perl

Question

I'm trying to follow this tutorial for my own code which basically right now reads a value into a scalar which is pushed into an array called states. However, it doesnt properly hash the function like in the tutorial and I believe its because the contents of the array isn't properly quoted.

I've tried

foreach (@states)
{
      q($_);
}

and

push @states, q($key);

but neither produces the necessary output. Currently my output displays as

NY, NJ, MI , NJ

when using

print join(", ", @states);

I want it to display

 'NY', 'NJ', 'MI' , 'NJ'

also @keys here represents the scalar value im adding into states (such as NY, NJ etc.) — Zee, Mar 31 '15 at 22:54

score 13 · Answer 1 · answered Mar 31 '15 at 23:04

13

Take states, map them to quoted strings, join by comma:

my @states = qw( NY NJ MI );
print join ', ', map "'$_'", @states;

answered Mar 31 '15 at 23:04

choroba

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unfortunately im reading it in from a file and storing it into a scalar so i cant directly do the qw() method – Zee Mar 31 '15 at 23:07
3

but in your question you show you have a @states array; if you don't, please modify your question. – ysth Mar 31 '15 at 23:24

score 1 · Accepted Answer · edited Apr 01 '15 at 00:12

1

To add quotes around a value you can use double-quoted string interpolation:

"'$_'"

Or you can use string concatenation:

"'".$_."'"

So you can write your foreach loop as follows:

foreach (@states) {
    $_ = "'$_'";
}

Note that $_ must be assigned, otherwise the body of the loop has no effect (this is the case with your q($_); code).

Full demo:

use strict;
use warnings;

my @states = qw(NY NJ MI NJ);

foreach (@states) {
    $_ = "'$_'";
}

print(join(', ', @states ));

'NY', 'NJ', 'MI', 'NJ'

edited Apr 01 '15 at 00:12

TLP

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answered Mar 31 '15 at 23:03

bgoldst

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I'm confused. Who downvoted my answer? And, more importantly, why? – bgoldst Mar 31 '15 at 23:47

score 1 · Answer 3 · answered Jul 04 '19 at 08:12

One other way:

use strict;
use warnings;

my @states = qw/ NY NJ MI NJ /;
my $output = join ', ', map qq/'$_'/, @states;

print $output;

Would result to a formatted list (string) of single quoted elements, each separated as you expect.

'NY', 'NJ', 'MI', 'NJ'

Add quotes to all elements inside of an array in perl

3 Answers3