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

A regex? 

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

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

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

U28geW91IGNhbiBhbGwgcm90MTMgY
W5kIHBhY2soKS4gQnV0IGRvIHlvdS
ByZWNvZ25pc2UgQmFzZTY0IHdoZW4
geW91IHNlZSBpdD8gIC0tIEp1ZXJk

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(MeowChow) Re5: Help with number conversion
by MeowChow (Vicar) on Apr 03, 2002 at 10:15 UTC
    You can get a substantial improvement over the builtin sprintf with: 
      substr "000$num", -3

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    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%      --

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       MeowChow                                   
               s aamecha.s a..a\u$&owag.print
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