FAQ 4.54 Why does defined() return true on empty arrays and hashes? - comp.lang.perl.misc

Message from discussion FAQ 4.54 Why does defined() return true on empty arrays and hashes?

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More options May 16, 9:03 pm

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From: PerlFAQ Server <br...@stonehenge.com>

Date: Fri, 16 May 2008 18:03:02 -0700

Local: Fri, May 16 2008 9:03 pm

Subject: FAQ 4.54 Why does defined() return true on empty arrays and hashes?

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This is an excerpt from the latest version perlfaq4.pod, which
comes with the standard Perl distribution. These postings aim to
reduce the number of repeated questions as well as allow the community
to review and update the answers. The latest version of the complete
perlfaq is at http://faq.perl.org .

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4.54: Why does defined() return true on empty arrays and hashes?

The short story is that you should probably only use defined on scalars
or functions, not on aggregates (arrays and hashes). See "defined" in
perlfunc in the 5.004 release or later of Perl for more detail.

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