{if (0 == $foo) vs if ($foo == 0)} The reason some people recommend the latter is because if you accidently type the == equality operator as the = assignment operator, you will get an error (not so for the former). Since I vary rarely get bitten by this, I still use the former.

That's a C thing; that is, a practise that was used among C programmers long before Perl programmers started coding.

It's not really necessary to do so in Perl; with warnings on, if you mistake the operator, Perl will warn (Found = in conditional, should be == at ...). I think some C compilers (like gcc) will warn if you have an assignment in a conditional as well; which can be disabled by using an additional set of parenthesis.

In reply to Re^2: Avoiding silly programming mistakes by JavaFan
in thread Avoiding silly programming mistakes by missingthepoint

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, 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.