Re: If the first four characters are "0000", then do {}

[Daniel Brown <danbrown@xxxxxxx>]

On Mon, Jan 25, 2010 at 22:51, Daevid Vincent <daevid@xxxxxxxxxx> wrote:
>> -----Original Message-----
>> From: parasane@xxxxxxxxx [mailto:parasane@xxxxxxxxx] On
>> Behalf Of Daniel Brown
>> Sent: Monday, January 25, 2010 6:43 PM
>> To: John Taylor-Johnston
>> Cc: PHP-General
>> Subject: Re:  If the first four characters are "0000", then do {}
>>
>> On Mon, Jan 25, 2010 at 21:36, John Taylor-Johnston
>> <John.Taylor-Johnston@xxxxxxxxxxxxxxxxxxxxx> wrote:
>> > I am reading the manual: http://ca.php.net/manual/en/ref.strings.php
>> >
>> > $mydata->restored = "0000-00-00";
>>
>> <?php
>>
>> $o[] = '0942-23-23';
>> $o[] = '0000-00-00';
>> $o[] = '1238-00-00';
>> $o[] = '0001-23-45';
>> $o[] = '0000-11-22';
>>
>> for($i=0;$i<count($o);$i++) {
>>         if(preg_match('/^[0]{4,}\-/U',$o[$i])) {
>>                 echo "Offset #".$i." matches: ".$o[$i].PHP_EOL;
>>         }
>> }
>> ?>
>
> Holy macaroni. Talk about overkill!
>
> if (substr($mydata->restored,0,4) == "0000") { }

    Overkill?

<?php

$o[] = '0942-23-23';
$o[] = '0000-00-00';
$o[] = '1238-00-00';
$o[] = '0001-23-45';
$o[] = '0000-11-22';

$now = microtime();

for($i=0;$i<count($o);$i++) {
       if(preg_match('/^[0]{4,}\-/U',$o[$i])) {
               //echo "Offset #".$i." matches: ".$o[$i].PHP_EOL;
       }
}

echo (microtime(1) - $now)."\n";


$later = microtime();

for($i=0;$i<count($o);$i++) {
        if(substr($o[$i],0,4) == "0000") {
                //echo "Offset #".$i." matches: ".$o[$i].PHP_EOL;
        }
}

echo (microtime(1) - $later)."\n";

?>

 Sample Output:

1264522257.0001
1264522257

    The preg_match() method, which is more expandable and adaptable
than relying on static position, took less than one-ten-thousandths of
a second longer to calculate than substr().

    Just an FYI before you start worshipping pasta, Mr. Vincent.  ;-P

-- 
</Daniel P. Brown>
daniel.brown@xxxxxxxxxxxx || danbrown@xxxxxxx
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