How can I print the elements of an array repeated twice each side-by-side?

Question

Please, I have the following line of code to write the header of a file, but I'd like to print each element of the array @order twice side-by-side. For example: $1 $1 $2 $2 $3 $3... in a way that I would have each pair of columns of my output file with the same name.

print(join("\t", "Case_ID", "State", "Ind", "DoB", @order) . "\n");

Can I do something simple or I have to loop over the array to repeat the elements before I print?

Thanks!

Answer 1

You have to loop anyway, but you can use map for syntactic elegance:

# map { $_, $_ } @order


print join("\t", "Case_ID", "State", "Ind", "DoB", map { $_, $_ }  @order))
       . "\n";