CODEWITHSUNDEEP
perl
gatorreina
gatorreina

Reputation: 960

How to make a non-interpolate string interpolate in Perl

How can I make the string below interpolate once it's determined that it has a '$' in it?

use strict;

my $yrs;
my $stg = 'He is $yrs years old.';

if ($stg =~ /[@#\$\%\/]/) {

    print "Matched dollar sign.\n";
    $yrs = '4';
    
} else {

    print "No Match.\n";

}

print "Year's scalar: $yrs\n";
print $stg . "\n";

I get:

He is $yrs years old.

I would like to get:

He is 4 years old.

Upvotes: 3

Views: 125

Answers (2)

brian d foy
brian d foy

Reputation: 132802

I'd probably write that with sprintf:

my $template = 'He is %d years old.';
my $output = sprintf $template, $years;

Upvotes: 1

ikegami
ikegami

Reputation: 385764

You are trying to write a template system. There are plenty of those around, so you don't have to go to through the trouble of writing your own.

use Template qw( );

my $template = 'He is [% years %] years old.';

my $vars = {
   years => 4,
};

my $tt = Template->new();
$tt->process(\$template, $vars, \my $output)
   or die($tt->error());

say $output;

Upvotes: 6

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