Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
@stuff = "This","That","Other";

When I first saw this and other, similar code fragments in this thread, my first expectation was that the comma expression  "This","That","Other" would evaluate to the right-most list item, "Other". After all, that's the rule: Evaluate left side, throw away, return right side in left-associative fashion.

After a bit of thought, I realized that the rule is to evaluate the leftmost expression, toss the result, evaluate and return the result of the rightmost expression, left-associative. Of course, the leftmost expression has a side effect: it creates and initializes the  @stuff array. The following helped me elucidate the process:

>perl -wMstrict -MO=Deparse,-p -le "my @stuff = 'One', 'Two', 'Three'; print qq{(@stuff)}; ;; my @stoff = scalar('Eine', 'Zwei', 'Drei'); print qq{(@stoff)}; ;; my @sniff = scalar(my @snarf = '111', '222', '333'); print qq{sniff: (@sniff) snarf: (@snarf)}; ;; my @stiff = ('Uno', 'Dos', 'Tres'); print qq{(@stiff)}; " Useless use of a constant (Eine) in void context at -e line 1. Useless use of a constant (Zwei) in void context at -e line 1. Useless use of a constant (222) in void context at -e line 1. Useless use of a constant (Two) in void context at -e line 1. Useless use of a constant (Three) in void context at -e line 1. BEGIN { $^W = 1; } BEGIN { $/ = "\n"; $\ = "\n"; } use strict 'refs'; ((my(@stuff) = 'One'), '???', '???'); print("(@stuff)"); (my(@stoff) = scalar(('???', '???', 'Drei'))); print("(@stoff)"); (my(@sniff) = scalar(((my(@snarf) = '111'), '???', '333'))); print("sniff: (@sniff) snarf: (@snarf)"); (my(@stiff) = ('Uno', 'Dos', 'Tres')); print("(@stiff)"); -e syntax OK >perl -wMstrict -le "my @stuff = 'One', 'Two', 'Three'; print qq{(@stuff)}; ;; my @stoff = scalar('Eine', 'Zwei', 'Drei'); print qq{(@stoff)}; ;; my @sniff = scalar(my @snarf = '111', '222', '333'); print qq{sniff: (@sniff) snarf: (@snarf)}; ;; my @stiff = ('Uno', 'Dos', 'Tres'); print qq{(@stiff)}; " Useless use of a constant (Eine) in void context at -e line 1. Useless use of a constant (Zwei) in void context at -e line 1. Useless use of a constant (222) in void context at -e line 1. Useless use of a constant (Two) in void context at -e line 1. Useless use of a constant (Three) in void context at -e line 1. (One) (Drei) sniff: (333) snarf: (111) (Uno Dos Tres)

In reply to Re: Newbie: query about array assignment by AnomalousMonk
in thread Newbie: query about array assignment by darren_uk

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!
  • 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
  • Outside of code tags, you may need to use entities for some characters:
            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?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others romping around the Monastery: (9)
    As of 2014-12-26 10:51 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      Is guessing a good strategy for surviving in the IT business?





      Results (171 votes), past polls