my @array1=(1,2,3); my @array2=(7,8); my @array3=(1,5,23,3); " @array1 , @array2 , @array3 " =~ / (\S+) .*?,.*? (\S+) .*?,.*? (\S+) (?{ push @res,"$1-$2-$3"; })(?!)/; print join ', ',@res;