... if $part->contentType is undefined ...

This is a little tricky, but to be precise, you're saying "if $part->contentType is false", then do something. In Perl, falsity is represented by any of: undef (the undefined value), "" (the empty string), 0 (numeric zero), or '0' (a string consisting of a single 0 character). Use the  // operator to test specifically for defined-ness.

Update: See also True and False (aka Booleans).

Give a man a fish:  <%-(-(-(-<

In reply to Re^3: What does the short circuit || mean ? by AnomalousMonk
in thread What does the short circuit || mean ? by peterr

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