Beefy Boxes and Bandwidth Generously Provided by pair Networks
Problems? Is your data what you think it is?

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??

To force a list context where there wouldn't be one otherwise, assign to an empty list.

Then how come Example 4 is

my ($x) = localtime(); # Example 4

and not

my $x = () = localtime();

I've never see assigning to an empty list used to force a list context. Assigning to an empty list is used to count the number of elements in a list (which has nothing to do with context).

In the case of badly written code, assigning to the empty list can differentiate between void and list context, but it never makes sense to use it to differentiate between scalar and list context as you show.

To force list context, one adds parens around the LHS of the assignment or use a list slice.

my ($x) = f(); # first element of list is assigned my $x = ( f() )[0]; # same, but overkill my $x = ( f() )[-1]; # last element of list is assigned my $x = ( f() )[0] # logical-or of the first elements || ( g() )[0]; # returned by f() and by g()

Update: Added example.

In reply to Re: Context tutorial by ikegami
in thread Context tutorial by kyle

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 scrutinizing the Monastery: (8)
    As of 2020-11-23 22:11 GMT
    Find Nodes?
      Voting Booth?

      No recent polls found