Actually, arrays cannot be undefined, just made empty (same with hashes). If you try undef @array in the debugger and then dump its value using the 'x' command, the effect is the same as if you had said @array = (), namely 'empty array'. (The same may be said for hashes, which under the above circumstances, produce the message, 'empty hash').
Only scalars may be truly undefined; undef is itself merely a value, albeit a special one. As a C/C++ programmer, I rather think of scalars analagous to pointers -- sort of "auto-allocating, auto-dereferencing, type-ambivalent pointers", but pointers nonetheless, with undef rather analagous to NULL.
If you GIVE a man a fish you feed him for a day
But, TEACH him to fish and you feed him for a lifetime
Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
Read Where should I post X? if you're not absolutely sure you're posting in the right place.
Please read these before you post! —
Posts may use any of the Perl Monks Approved HTML tags:
You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
- a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
Link using PerlMonks shortcuts! What shortcuts can I use for linking?
See Writeup Formatting Tips and other pages linked from there for more info.
| & || & |
| < || < |
| > || > |
| [ || [ |
| ] || ] ||