how to improve perf. ?

[erickrefener]

Hi,

I made a script which analyse very long strings and I need to make it
work differently depending of the 5 first chars of it.

I already do :

switch (true){
case ( ereg("12345", $data) ):
print '$data est un chaine 12345';
break;
case ( ereg("54321", $data) ):
print '$data est un chaine 54321';
break;
default:
print 'invalid data';
}

cause those first chars order doesn't matter, it can't be found in the
same order again ...

I know that there are lots of way to do this with php but could you tell
me which would the fastest way (talking about performance) to do it ?
(in order to make php not to analyse the entire string but only those 5
first chars ....)

thanks a lot,
erick

[Tom Thackrey]

On 16-Jan-2004, erickrefener <er***@spamitoudina.com> wrote:

I made a script which analyse very long strings and I need to make it
work differently depending of the 5 first chars of it.

I already do :

switch (true){
case ( ereg("12345", $data) ):
print '$data est un chaine 12345';
break;
case ( ereg("54321", $data) ):
print '$data est un chaine 54321';
break;
default:
print 'invalid data';
}

cause those first chars order doesn't matter, it can't be found in the
same order again ...

I know that there are lots of way to do this with php but could you tell
me which would the fastest way (talking about performance) to do it ?
(in order to make php not to analyse the entire string but only those 5
first chars ....)

thanks a lot,

Please cross-post in the future.

switch (substr($data,0,5))
{
case '12345':
...
case '54321':
...
}

--
Tom Thackrey
www.creative-light.com
tom (at) creative (dash) light (dot) com
do NOT send email to ja*********@willglen.net (it's reserved for spammers)

[Chung Leong]

First of all, what is the point of writing an if-else-if statement as a
switch statement?

As noted in the PHP manual preg_match() is faster than ereg. The problem
with you regular expression is you're telling it to search to whole text.
Put a ^ at the beginning to specify match at the beginning of the string.

if(preg_match("/^12345/", $data)) {
print '$data est un chaine 12345';
}
else if(preg_match("/^54321/", $data)) {
print '$data est un chaine 54321';
}
else {
}

Of course, the assumption here is that the actual regular expressions are
more complicated that a straight string comparison.

Uzytkownik "erickrefener" <er***@spamitoudina.com> napisal w wiadomosci
news:QL*******************@news20.bellglobal.com.. .

Hi,

I made a script which analyse very long strings and I need to make it
work differently depending of the 5 first chars of it.

I already do :

switch (true){
case ( ereg("12345", $data) ):
print '$data est un chaine 12345';
break;
case ( ereg("54321", $data) ):
print '$data est un chaine 54321';
break;
default:
print 'invalid data';
}

cause those first chars order doesn't matter, it can't be found in the
same order again ...

I know that there are lots of way to do this with php but could you tell
me which would the fastest way (talking about performance) to do it ?
(in order to make php not to analyse the entire string but only those 5
first chars ....)

thanks a lot,
erick