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evaluating a null value in an array

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  evaluating a null value in an array bill <nobody@spamcop.net> - 2011-05-07 07:27 -0400
    Re: evaluating a null value in an array Jerry Stuckle <jstucklex@attglobal.net> - 2011-05-07 07:36 -0400
      Re: evaluating a null value in an array Gregor Kofler <usenet@gregorkofler.com> - 2011-05-07 18:35 +0200
        Re: evaluating a null value in an array dougatmilmacdotcom@example.com (Doug Miller) - 2011-05-07 23:46 +0000
        Re: evaluating a null value in an array Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2011-05-08 13:56 +0200
          Re: evaluating a null value in an array Gregor Kofler <usenet@gregorkofler.com> - 2011-05-08 20:18 +0200
      Re: evaluating a null value in an array bill <nobody@spamcop.net> - 2011-05-07 13:50 -0400
    Re: evaluating a null value in an array Denis McMahon <denis.m.f.mcmahon@gmail.com> - 2011-05-07 15:30 +0000
      Re: evaluating a null value in an array Gregor Kofler <usenet@gregorkofler.com> - 2011-05-07 18:34 +0200

#1459 — evaluating a null value in an array

I have an array of values, one of which might be null.

This statement fails
if ( ($dos <= $insInfo[3]) or($dos == '0000-00-00'))

with the error:
  Notice: Undefined offset: 3 in 
/var/www/MP2010-v2/classes/cDollar.php on line 237

when $insInfo[3] is NULL.

I figured I could shortcut the evaluation with:

if ( ( is_null($insInfo[3])) or($dos <= $insInfo[3]) or($dos == 
'0000-00-00'))

but I get the same error.

I sure would appreciate:
   knowing why I get the error, and
   a suggestion on how to evaluate this value.

bill

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#1461

On 5/7/2011 7:27 AM, bill wrote:
> I have an array of values, one of which might be null.
>
> This statement fails
> if ( ($dos <= $insInfo[3]) or($dos == '0000-00-00'))
>
> with the error:
> Notice: Undefined offset: 3 in /var/www/MP2010-v2/classes/cDollar.php on
> line 237
>
> when $insInfo[3] is NULL.
>
> I figured I could shortcut the evaluation with:
>
> if ( ( is_null($insInfo[3])) or($dos <= $insInfo[3]) or($dos ==
> '0000-00-00'))
>
> but I get the same error.
>
> I sure would appreciate:
> knowing why I get the error, and
> a suggestion on how to evaluate this value.
>
> bill

Is it null, or is it not set?  There is a difference!

Try isset() instead of is_null().

-- 
==================
Remove the "x" from my email address
Jerry Stuckle
JDS Computer Training Corp.
jstucklex@attglobal.net
==================

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#1468

Am 2011-05-07 13:36, Jerry Stuckle meinte:
> On 5/7/2011 7:27 AM, bill wrote:
>> I have an array of values, one of which might be null.
>>
>> This statement fails
>> if ( ($dos <= $insInfo[3]) or($dos == '0000-00-00'))
>>
>> with the error:
>> Notice: Undefined offset: 3 in /var/www/MP2010-v2/classes/cDollar.php on
>> line 237
>>
>> when $insInfo[3] is NULL.
>>
>> I figured I could shortcut the evaluation with:
>>
>> if ( ( is_null($insInfo[3])) or($dos <= $insInfo[3]) or($dos ==
>> '0000-00-00'))
>>
>> but I get the same error.
>>
>> I sure would appreciate:
>> knowing why I get the error, and
>> a suggestion on how to evaluate this value.
>>
>> bill
> 
> Is it null, or is it not set?  There is a difference!

Which isset() won't spot.

http://php.net/manual/de/function.isset.php


Gregor


-- 
http://vxweb.net

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#1471

In article <iq3scb$gre$2@dont-email.me>, Gregor Kofler <usenet@gregorkofler.com> wrote:
>Am 2011-05-07 13:36, Jerry Stuckle meinte:
>> On 5/7/2011 7:27 AM, bill wrote:
>>> I have an array of values, one of which might be null.
>>>
>>> This statement fails
>>> if ( ($dos <= $insInfo[3]) or($dos == '0000-00-00'))
>>>
>>> with the error:
>>> Notice: Undefined offset: 3 in /var/www/MP2010-v2/classes/cDollar.php on
>>> line 237
>>>
>>> when $insInfo[3] is NULL.
>>>
>>> I figured I could shortcut the evaluation with:
>>>
>>> if ( ( is_null($insInfo[3])) or($dos <= $insInfo[3]) or($dos ==
>>> '0000-00-00'))
>>>
>>> but I get the same error.
>>>
>>> I sure would appreciate:
>>> knowing why I get the error, and
>>> a suggestion on how to evaluate this value.
>>>
>>> bill
>> 
>> Is it null, or is it not set?  There is a difference!
>
>Which isset() won't spot.

Nonetheless, isset() is the right function to use here. is_null($x) fails if 
$x is not set; isset($x) does not.

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#1474

Gregor Kofler wrote:

> http://php.net/manual/de/function.isset.php

In this international newsgroup (and maybe elsewhere), it is probably better 
to suggest

  <http://php.net/isset>

This takes advantage of several features of the PHP.net Web site:

  - The mirror will be chosen according to the visitor's geographic
    location (or their preferences), which should provide them with the
    fastest/most desirable viewing experience;

  - The language will be chosen according to visitor preferences (cookies)
    (although it must be said that the English version is apparently the
    most accurate and up-to-date one);

  - Whenever the documentation structure changes, relevant information
    can still be found; either through implicit redirection, or through
    the search results being displayed for parts of the documentation
    where redirection is not implemented.

Therefore, I have found this bookmarklet useful:

  http://php.net/%s


Regards,

PointedEars
-- 
Use any version of Microsoft Frontpage to create your site.
(This won't prevent people from viewing your source, but no one
will want to steal it.)
  -- from <http://www.vortex-webdesign.com/help/hidesource.htm> (404-comp.)

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#1476

Am 2011-05-08 13:56, Thomas 'PointedEars' Lahn meinte:
> Gregor Kofler wrote:
> 
>> http://php.net/manual/de/function.isset.php
> 
> In this international newsgroup (and maybe elsewhere), it is probably better 
> to suggest
> 
>   <http://php.net/isset>

Indeed. I normally both use and suggest the English version of the
manual. Googling for a quick link gave me the German version, and I
didn't pay enough attention.

Gregor

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#1470

On 5/7/2011 7:36 AM, Jerry Stuckle wrote:
> On 5/7/2011 7:27 AM, bill wrote:
>> I have an array of values, one of which might be null.
>>
>> This statement fails
>> if ( ($dos <= $insInfo[3]) or($dos == '0000-00-00'))
>>
>> with the error:
>> Notice: Undefined offset: 3 in
>> /var/www/MP2010-v2/classes/cDollar.php on
>> line 237
>>
>> when $insInfo[3] is NULL.
>>
>> I figured I could shortcut the evaluation with:
>>
>> if ( ( is_null($insInfo[3])) or($dos <= $insInfo[3]) or($dos ==
>> '0000-00-00'))
>>
>> but I get the same error.
>>
>> I sure would appreciate:
>> knowing why I get the error, and
>> a suggestion on how to evaluate this value.
>>
>> bill
>
> Is it null, or is it not set? There is a difference!
>
> Try isset() instead of is_null().

Exactly, when I use isset it does not error.
Thanks.

bill

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#1466

On Sat, 07 May 2011 07:27:21 -0400, bill wrote:

>    a suggestion on how to evaluate this value.

if (
        !(isset($insInfo[3]))    // $insInfo3 not defined
     || (is__null($insInfo[3]))  // $insInfo3 defined and null
     || ($dos <= $insInfo[3])    // $insInfo3 > $dos
     || ($dos == '0000-00-00')   // $dos null date
   ) 

Rgds

Denis McMahon

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#1467

Am 2011-05-07 17:30, Denis McMahon meinte:
> On Sat, 07 May 2011 07:27:21 -0400, bill wrote:
> 
>>    a suggestion on how to evaluate this value.
> 
> if (
>         !(isset($insInfo[3]))    // $insInfo3 not defined
>      || (is__null($insInfo[3]))  // $insInfo3 defined and null

Not necessary.

isset() also returns false when the tested variable is set to NULL [1].

$bar = NULL;
var_dump(isset($foo)); // FALSE
var_dump(isset($bar)); // FALSE

Gregor


[1]
http://php.net/manual/de/function.isset.php

-- 
http://vxweb.net

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