http://qs321.pair.com?node_id=156238


in reply to Help with number conversion

$number = 1; $number = "0".$number until length $number >= 3; print $number,"\n";

Hope that helps..

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Re: Re: Help with number conversion
by Juerd (Abbot) on Apr 03, 2002 at 07:57 UTC

    $number = 1;
    $number = "0".$number until length $number >= 3;
    print $number,"\n";

    I'm sure merlyn just wanted you to know that although this works as expected, there are better alternatives. To many, "Matt Wright" is a synonym for "clumsy code that does however do what it's supposed to do" (not to be taken literally: merlyn didn't ask if you went to school with clumsy code :)).

    Your approach is directly instructing Perl to do what you want it to do. If you feel comfortable with that, you should do it that way. But often there is some efficiency in both coding and run time to be gained when you use Perl's core functions. In this case, it'd be $number = sprintf '%03d', $number;, which is approximately 2.5 times as fast.

    Learn about sprintf. It can be very confusing at first, but the %-notation is easy to get used to.

    U28geW91IGNhbiBhbGwgcm90MTMgY
    W5kIHBhY2soKS4gQnV0IGRvIHlvdS
    ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
    geW91IHNlZSBpdD8gIC0tIEp1ZXJk
    

Re: Re: Help with number conversion
by crazyinsomniac (Prior) on Apr 03, 2002 at 07:39 UTC
•Re: Re: Help with number conversion
by merlyn (Sage) on Apr 03, 2002 at 05:31 UTC
    $number = "0".$number until length $number >= 3;
    Did you and Matt Wright go to school together?

    {sigh}

    -- Randal L. Schwartz, Perl hacker


    update: You know, when I first posted my comment, and the post was something Matt-Wright-ish, as I commented above, I left my vote neutral. But when it was changed to:
    You know what? merlyn wins. Forget it. I'll stop offering advice before running it past him first.
    I finally invoked a downvote. Don't post code here unless you can take open criticism, including a little ribbing and being compared to the bad-code-poster-Child.

      This is of course a job for a regex ;-)

      $number = 42; s/.*/"s||000$number|&&join'',reverse chop,chop,chop"/eieio; print;

      cheers

      tachyon

      s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

        A regex?

        $number = 42; $number = (' ' x (3 - length $number)) . $number | "000";
        Oh wait, let's not do string bit operations ;)
        $number = 42; $number = ('0' x (3 - length $number)) . $number;
        (The latter is only 50% less efficient than sprintf)

        U28geW91IGNhbiBhbGwgcm90MTMgY
        W5kIHBhY2soKS4gQnV0IGRvIHlvdS
        ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
        geW91IHNlZSBpdD8gIC0tIEp1ZXJk