Here are four equivalent declarations using "" and qq{}.

#/usr/bin/perl

use strict; use warnings;
use Test::More tests =>4 ;

my $a1 = qq{a\r\nb\r\nc\r\n};
my $a2 = qq{a\r
b\r
c\r
};
my $b1 = "a\r\nb\r\nc\r\n";
my $b2 = "a\r
b\r
c\r\n";

is( $a1, $a2, "a1 and a2 are the same");
is( $b1, $b2, "b1 and b2 are the same");
is( $a1, $b1, "a1 and b1 are the same");
is( $a2, $b2, "a2 and b2 are the same");

__END__
1..4
ok 1 - a1 and a2 are the same
ok 2 - b1 and b2 are the same
ok 3 - a1 and b1 are the same
ok 4 - a2 and b2 are the same
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1 -- except for the semantics used for escaping, qq will escape double-quotes in the string.