use strict;
use warnings;

my $pic = 1;
my $v = {R3R3_1_IF => 100};

print "Hello world. $v->{R3R3_$pic\_IF}\n";

##</code><code>##

Backslash found where operator expected at mytest.pl line 9, near "$pic\"
	(Missing operator before \?)
Bareword "_IF" not allowed while "strict subs" in use at mytest.pl line 9.
mytest.pl had compilation errors.
use warnings;
use strict;
my $pic = 1;
my $v = {'R3R3_1_IF', 100};
print "Hello world. $$v{$pic->R3R3_(\'_IF')}\n";

##</code><code>##

use strict;
use warnings;

my $pic = 1;
my $v = {R3R3_1_IF => 100};

print "Hello world. $v->{R3R3_${pic}_IF}\n";

##</code><code>##

Bareword found where operator expected at mytest.pl line 9, near "${pic}_IF"
	(Missing operator before _IF?)
Bareword "_IF" not allowed while "strict subs" in use at mytest.pl line 9.
mytest.pl had compilation errors.
use warnings;
use strict;
my $pic = 1;
my $v = {'R3R3_1_IF', 100};
print "Hello world. $$v{$pic->R3R3_('_IF')}\n";