Beefy Boxes and Bandwidth Generously Provided by pair Networks
The stupid question is the question not asked
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
keys just loops over calls to each, but does it somewhat more efficiently than you can in Perl. Which is why when you return the whole list, keys is modestly faster.

But when you leave the loop very early with each, well that is a lot faster than going through all of them! (Hint, you are breaking out after an entry or two.)

UPDATE
My wording confused people. A foreach loop has to build a complete list of values before it does any processing. (Except for a hack for the range operator.) A while loop processes entries as it walks through the list. So the keys approach has to build the whole list even though most will be ignored, the each approach does not. But when you go through all of them, the each approach is doing basically what foreach did up front.

That make sense?


In reply to Re: each or keys? by tilly
in thread each or keys? by rdw

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.
  • 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 drinking their drinks and smoking their pipes about the Monastery: (9)
    As of 2021-04-13 07:56 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      No recent polls found

      Notices?