So, what's in @dna then? Letters? Strings? If you have the sequence in a sequence $dna, you could do: 
    print "$_ " for $dna =~ /(?=(..))/g;

[download]

If you have individual letters in an array, you could use: 

    print @dna [$_ - 1, $_], " " for 1 .. $#dna;

[download]

Abigail

In reply to Re: loop and counter question by Abigail-II
in thread loop and counter question by Anonymous Monk

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