in reply to •Re: Re: Help with number conversion
in thread Help with number conversion

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

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

[download]

cheers

tachyon

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

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Re: Re: •Re: Re: Help with number conversion
by Juerd (Abbot) on Apr 03, 2002 at 09:22 UTC

    A regex? 

    $number = 42;
$number = (' ' x (3 - length $number)) . $number | "000";

    [download]
    Oh wait, let's not do string bit operations ;) 
    $number = 42;
$number = ('0' x (3 - length $number)) . $number;

    [download]
    (The latter is only 50% less efficient than sprintf) 

    U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

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[d/l]
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      You can get a substantial improvement over the builtin sprintf with: 
        substr "000$num", -3

      [download]
        
      use strict;
use Benchmark qw(cmpthese);

my $num = 42;
cmpthese (-3, {
  sprintf => sub { sprintf '%03d', $num },
  concat  => sub { ('0' x (3 - length $num)).$num },
  substr  => sub { substr "000$num", -3 },
});

            Rate  concat sprintf  substr
concat  244047/s      --    -10%    -36%
sprintf 269956/s     11%      --    -29%
substr  381628/s     56%     41%      --

      [download]
         MeowChow                                   
               s aamecha.s a..a\u$&owag.print
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[d/l]
[select]

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