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To: Stefan Walk <swalk@prp.physik.tu-darmstadt.de>
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Subject: Re: [PHP-DEV] variable_exists() patch
From: waboring@3gstech.com (walt boring)

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Stefan Walk wrote:

>On Thu, Aug 14, 2003 at 11:15:51AM -0700, walt boring wrote:
>  
>
>>I for one would like to see something like variable_exists(), as I am 
>>very annoyed with
>>the logic of isset() returning false if the variable exists and has a 
>>value of null. 
>>    
>>
>[snip] 
>  
>
>> I for one would much rather do
>> if ( variable_exists($var) ) {}  versus
>>if (isset($var) || is_null($var)) {}
>>    
>>
>
>When do you need to do that? I can't think of many situations where it
>would be neccessary to check if a variable really exists.
>  
>
It can happen quite easily.  I always develop with full warnings/errors on.
So if for example a var isn't set for whatever reason,  then trying to 
access the
variable will throw a php Notice.  variable_exists() would prevent that, 
as does isset().
isset() would work for my example below, but it still is a 'broken' 
function in my opinion.

if ($var) {  // <-- you'll get a php notice on this line
  switch ($var) {
    ...
  }

}

versus doing

if (variable_exists($var))  {  //no php notices here
  switch($var) {
   ...
  }
}

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