Verifying a certain amount of numbers

I would like to know how to verify that there are 6 numbers (only numbers in
a field)
that will be submitted to a database? Any clues!

if(!ereg('^[0-9]{6}$',$string) die('not six numbers');

you might want to trim off white space first.

Ron Allen wrote:

> I would like to know how to verify that there are 6 numbers (only numbers in
> a field)
> that will be submitted to a database? Any clues!
>
>
>

If you care about performance at all, try and find away around the
problem without regular expressions...

I tested

if( (strlen($str) == 6) && (is_int($str)) )

vs

if(ereg('^[0-9]{6}$',$str))


....on my LAN test server with 100000 iterations, and the regexp was
nearly 2 times slower than the first solution. IMHO, it's also faster
to read and modify the first solution too -- especially for those with
minimal regexp experience.


Justin


On Wednesday, July 16, 2003, at 11:07 PM, Ron Allen wrote:

> I would like to know how to verify that there are 6 numbers (only
> numbers in
> a field)
> that will be submitted to a database? Any clues!

Justin French <justin@indent.com.au> wrote:
> If you care about performance at all, try and find away around the
> problem without regular expressions...
>
> I tested
>
> if( (strlen($str) == 6) && (is_int($str)) )
>
> vs
>
> if(ereg('^[0-9]{6}$',$str))
>
>
> ...on my LAN test server with 100000 iterations, and the regexp was
> nearly 2 times slower than the first solution. IMHO, it's also faster

Excellent point! I find my self using regex's a bit to often when there
are other solutions available.

btw, have you ever tested the difference between

if(ereg('^[0-9]{6}$',$str))
if(preg_grep('^[0-9]{6}$',$str))

I've been meaning to find out advantages/disadvantages with PERL vs.
POSIX compatible.


Curt.
--

"Curt Zirzow" <curt@zirzow.dyndns.org> wrote in message
news:20030716141706.GR50106@bagend.shire...
> Excellent point! I find my self using regex's a bit to often when there
> are other solutions available.
>
> btw, have you ever tested the difference between
>
> if(ereg('^[0-9]{6}$',$str))
> if(preg_grep('^[0-9]{6}$',$str))
>
> I've been meaning to find out advantages/disadvantages with PERL vs.
> POSIX compatible.
Without getting too far astray from the real subject, I was once writing a
script opening a textfile and modifying the whole contents to create a new
file, using POSIX compatible expressions. My script timed out (30sec+) at
some 400kb. I read Perl compatible was faster, and so I modified my script
to use those. Result : done in a couple of secs.

I bet it depends on the type of expression (these were a bunch of replaces)
but for larger input or many iterations I'd rather use Perl compatible...

--
[Win2000 | Apache/1.3.23]
[PHP/4.2.3 | MySQL/3.23.53]

Ivo Fokkema
PHP & MySQL programmer
Leiden University Medical Centre
Netherlands

I'm pretty sure there will be a problem with using the is_int()
function. A similar problem was discussed a few weeks ago on this list
and is_int() will return true for a "number" like 1000e2. The "e" being
treated as an exponential representation of an integer.

It might be more reliable to add or subtract 0 from the "string" and
see if it changes. Something like:
if( (strlen($str)==6) && ( strcmp(($str-0),$str)==0))

It may just be easier to use ereg if you won't be looping through a
bunch of numbers. I don't know what the performance difference is
between the above function and ereg or preg.

On Wednesday, July 16, 2003, at 09:43 AM, Justin French wrote:

> I tested
>
> if( (strlen($str) == 6) && (is_int($str)) )
>
> vs
>
> if(ereg('^[0-9]{6}$',$str))
>
--
Brent Baisley
Systems Architect
Landover Associates, Inc.
Search & Advisory Services for Advanced Technology Environments
p: 212.759.6400/800.759.0577

Brent Baisley <brent@landover.com> wrote:
> I'm pretty sure there will be a problem with using the is_int()
> function. A similar problem was discussed a few weeks ago on this list
> and is_int() will return true for a "number" like 1000e2. The "e" being
> treated as an exponential representation of an integer.

I thought that was is_numeric(), I'll have to test that.

> It might be more reliable to add or subtract 0 from the "string" and
> see if it changes. Something like:
> if( (strlen($str)==6) && ( strcmp(($str-0),$str)==0))

True that should work but it is kinda confusing code for a newbie. It
doesnt really explain well what your doing.

> --
> Brent Baisley
> Systems Architect
> Landover Associates, Inc.
> Search & Advisory Services for Advanced Technology Environments
> p: 212.759.6400/800.759.0577
>
>

Curt
--

Yes, use preg_match("/^[0-9]{6}$/",$str) since it takes care of both
number and length.
You dont want to you is_numeric(), because that will match "4e5", etc..etc..


Brent Baisley wrote:

> I'm pretty sure there will be a problem with using the is_int()
> function. A similar problem was discussed a few weeks ago on this list
> and is_int() will return true for a "number" like 1000e2. The "e"
> being treated as an exponential representation of an integer.
>
> It might be more reliable to add or subtract 0 from the "string" and
> see if it changes. Something like:
> if( (strlen($str)==6) && ( strcmp(($str-0),$str)==0))
>
> It may just be easier to use ereg if you won't be looping through a
> bunch of numbers. I don't know what the performance difference is
> between the above function and ereg or preg.
>
> On Wednesday, July 16, 2003, at 09:43 AM, Justin French wrote:
>
>> I tested
>>
>> if( (strlen($str) == 6) && (is_int($str)) )
>>
>> vs
>>
>> if(ereg('^[0-9]{6}$',$str))
>>

Justin French <justin@indent.com.au> wrote:
> If you care about performance at all, try and find away around the
> problem without regular expressions...
>
> I tested
>
> if( (strlen($str) == 6) && (is_int($str)) )
>
I did some more tests on this problem is that $str is still considered a
string and not an integer here is my test script and results:

<?php
// is_int() testing

// standard string
$str = "123";
if (is_int($str)) print "$str: yes \n";
else print "$str: no \n";

//cast to integer
$str = (integer)"123";
if (is_int($str)) print "$str: yes \n";
else print "$str: no \n";

// implied cast to integer
$str = "123";
$str += 0;
if (is_int($str)) print "$str: yes \n";
else print "$str: no \n";

// force to be integer
$str = "123";
settype($str, 'integer');
if (is_int($str)) print "$str: yes \n";
else print "$str: no \n";

/*
Results:

123: no
123: yes
123: yes
123: yes

*/
?>

On Thursday, July 17, 2003, at 12:17 AM, Curt Zirzow wrote:

> Excellent point! I find my self using regex's a bit to often when there
> are other solutions available.
>
> btw, have you ever tested the difference between
>
> if(ereg('^[0-9]{6}$',$str))
> if(preg_grep('^[0-9]{6}$',$str))
>
> I've been meaning to find out advantages/disadvantages with PERL vs.
> POSIX compatible.

Hi,

I haven't, but feel free to do your own :)

Use the sample found on http://au.php.net/microtime

Justin