I don't think there is any significant difference between "" and ''. Consider that the metachar \ is still checked in single quoted strings, this means that both types undergo some char check. I find '' to be easier to read, which is a good enough reason to use it (in my book).

Another point, however, is that I generally encourage people to put the constant first in a comparison. This may seem odd, because its the reverse of how we like to read it, but it results in fewer typos of = versus == type. Really this is the only place it matters, but how often have you tweaked a >= into an = or tweaked an eq into an = ??? So I would check that ( '' ne $teststring ). Also, you know that '' is the equivalence of false. (Of course, so is "0", which is why you would want to be explicit.)

In reply to Re: A better non-existant string... by Adam
in thread A better non-existant string... by lzcd

Title:
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, details, 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, summary, 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.