In a single line ...

my @lastnames = map { (split ",")[1] } split "\n", $scalar;
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Uses an array slice; the map returns the second element of each line.

HTH!

perl -e 'print "How sweet does a rose smell? "; chomp ($n = <STDIN>); 
+$rose = "smells sweet to degree $n"; *other_name = *rose; print "$oth
+er_name\n"'
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