Req #69626 [NEW]: how check variable be defined ? how check variable be exists
From: hark110 at 63 dot com
Operating system:
PHP version: 5.6.8
Package: PHP Language Specification
Bug Type: Feature/Change Request
Bug description:how check variable be defined ? how check variable be exists
Description:
------------
current php no best way check a variable whether be defined, only like
below:
if check $a whether be defined
in global varibale:
array_key_exists('a', $GLOBALS);
in function or method:
array_key_exists('a',get_defined_vars())
because isset, empty is not trust, see test script
Test script:
---------------
<?php
function test() {
//defined variable
$a = null;
var_dump(isset($a)); //false
var_dump(is_null($a));//true
var_dump(empty($a)); //true
//undefined variable
var_dump(isset($b));//false
var_dump(empty($a)); //true
var_dump(@is_null($c));//true, Notice: Undefined variable: a
var_dump(get_defined_vars());//$b,$c undefined, $a is defined and
value is NULL
//be unset() variable
$d;
unset($d);
var_dump(empty($a)); //true
var_dump(isset($d));//false
var_dump(@is_null($d));//true,Notice: Undefined variable: a
var_dump(get_defined_vars());//$b,$c undefined,$d be unset and
defined, $a is defined and value is NULL
//empty string variable
$e = '';
var_dump(empty($e)); //true
var_dump(isset($e)); // true
var_dump(is_null($e)); //false
var_dump(get_defined_vars());//$b,$c undefined,$d be unset and
undefined, $a is defined and value is NULL, $e is defined and value is
empty string
}
test();
Expected result:
----------------
<?php
$a;
var_dump(isset($a)); // is false
Actual result:
--------------
<?php
$a;
var_dump(isset($a)); // is true
?>
or
<?php
$a;
var_dump(isdefined($a)); //is true
--
Edit bug report at https://bugs.php.net/bug.php?id=69626&edit=1
--
Try a snapshot (PHP 5.4): https://bugs.php.net/fix.php?id=69626&r=trysnapshot54
Try a snapshot (PHP 5.5): https://bugs.php.net/fix.php?id=69626&r=trysnapshot55
Try a snapshot (trunk): https://bugs.php.net/fix.php?id=69626&r=trysnapshottrunk
Fixed in SVN: https://bugs.php.net/fix.php?id=69626&r=fixed
Fixed in release: https://bugs.php.net/fix.php?id=69626&r=alreadyfixed
Need backtrace: https://bugs.php.net/fix.php?id=69626&r=needtrace
Need Reproduce Script: https://bugs.php.net/fix.php?id=69626&r=needscript
Try newer version: https://bugs.php.net/fix.php?id=69626&r=oldversion
Not developer issue: https://bugs.php.net/fix.php?id=69626&r=support
Expected behavior: https://bugs.php.net/fix.php?id=69626&r=notwrong
Not enough info: https://bugs.php.net/fix.php?id=69626&r=notenoughinfo
Submitted twice: https://bugs.php.net/fix.php?id=69626&r=submittedtwice
register_globals: https://bugs.php.net/fix.php?id=69626&r=globals
PHP 4 support discontinued: https://bugs.php.net/fix.php?id=69626&r=php4
Daylight Savings: https://bugs.php.net/fix.php?id=69626&r=dst
IIS Stability: https://bugs.php.net/fix.php?id=69626&r=isapi
Install GNU Sed: https://bugs.php.net/fix.php?id=69626&r=gnused
Floating point limitations: https://bugs.php.net/fix.php?id=69626&r=float
No Zend Extensions: https://bugs.php.net/fix.php?id=69626&r=nozend
MySQL Configuration Error: https://bugs.php.net/fix.php?id=69626&r=mysqlcfg
Thread (1 message)
- hark110 at 63 dot com