exists operates on hashes only (as the error suggests): it checks whether the key given exists in the hash. To test for the existence of an array element, use defined: 
print DATA "\+$exp[1]" if defined $exp[1];

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The above code snippet is untested, BTW.

CU
Robartes-

In reply to Re: exists and defined functions by robartes
in thread exists and defined functions by arrow

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