Beefy Boxes and Bandwidth Generously Provided by pair Networks
Pathologically Eclectic Rubbish Lister

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
For good reasons operators in Perl do type conversions!

  • ==, + - *   and so on do numification so undef is considered 0

  • eq, . and so on do stringification so undef is considered empty string "".

    Anyway using warnings you'll often get "Use of uninitialized value" messages.

    I do not understand what your intentions are, but if you wanna test for undef use the designated functions defined or //


    Equality Operators in perlop

           Binary "==" returns true if the left argument is numerically equal to
           the right argument.
           Binary "eq" returns true if the left argument is stringwise equal to
           the right argument.

    Cheers Rolf

    In reply to Re: How come undef eq '' ?? by LanX
    in thread How come undef eq '' ?? by tmharish

    Use:  <p> text here (a paragraph) </p>
    and:  <code> code here </code>
    to format your post; it's "PerlMonks-approved HTML":

  • 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:
    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
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others chanting in the Monastery: (10)
    As of 2015-11-26 18:46 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (705 votes), past polls