and and or were introduced as lower precedence versions of && and ||, infact their precedence is guaranteed to be lower than any other operator so you can use them in places where otherwise you would have to use additional or otherwise unnecessary parentheses to ensure the correct meaning of a statement. This is probably clearest seen in: 

open HANDLE, $file || die $!;

[download]
which is almost certainly a mistake (i.e. it won't die unless $file has a false value because the || has higher precedence than the comma in the argument list.) If you want to use || you would need to use the parentheses thus: 
open(HANDLE, $file) || die $!;

[download]
Whereas: 
open HANDLE, $file or die $!;

[download]
works fine.

In most places it is mostly a stylistic choice of whether to use the higher priority operator and more parentheses or not.

/J\

In reply to Re: && and and (well, you try searching for an answer) by gellyfish
in thread && and and (well, you try searching for an answer) by Melly

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.