Req #63713 [Opn->Wfx]: Need an "UNDEFINED" type
Edit report at https://bugs.php.net/bug.php?id=63713&edit=1
ID: 63713
Updated by: aharvey@php.net
Reported by: liquid_nitrogen_4ever at yahoo dot com
Summary: Need an "UNDEFINED" type
-Status: Open
+Status: Wont fix
Type: Feature/Change Request
Package: Variables related
PHP Version: Irrelevant
Block user comment: N
Private report: N
New Comment:
I don't see much value in this: it's an unusual use case, would require engine changes,
and you can already check if a variable is defined with
array_key_exists('notExistentVariable', get_defined_vars()).
Previous Comments:
------------------------------------------------------------------------
[2012-12-06 17:42:43] liquid_nitrogen_4ever at yahoo dot com
Description:
------------
Consider the following scenario currently in PHP:
var_dump($notExistentVariable);
-> NOTICE: Undefined variable notHere on line 1
NULL
isset($notExistentVariable);
-> FALSE
$foo = null;
var_dump($foo);
-> NULL
isset($foo);
-> FALSE
If there were an UNDEFINED "type" (in the same sense that there is a NULL), the
above scenarios would change to:
var_dump($notExistentVariable);
-> UNDEFINED
isset($notExistentVariable);
-> FALSE
$foo = null;
var_dump($foo);
-> NULL
isset($foo);
-> TRUE
However, unlike NULL, you would NOT be allowed to explicitly initialize
something to UNDEFINED.
$x=UNDEFINED;//error: if you want it to be undefined, don't declare it.
However, having just:
$x;
makes sense (to me at least) as shortcut to:
$x=NULL;
In other words, if a variable is declared but not explicitly initialized, it
will implicitly be set to NULL (which is
essentially what you are already doing, but one can't really differentiate
between declared and undeclared variables).
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=63713&edit=1
Thread (3 messages)