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Bugs & Features
<?php session_start(); function foo() { $t = '_SESSION'; $a = $$t; // not work $b = ${'_SESSION'}; // works var_dump($a, $b); } foo();
Output for 5.2.3 - 5.6.25, hhvm-3.10.0 - 3.12.0, 7.0.0 - 7.1.0
Notice: Undefined variable: _SESSION in /in/ZZB0I on line 6 NULL array(0) { }
Output for 5.0.4 - 5.2.2
Warning: session_start(): Cannot send session cookie - headers already sent in /in/ZZB0I on line 2 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /in/ZZB0I:2) in /in/ZZB0I on line 2 Notice: Undefined variable: _SESSION in /in/ZZB0I on line 6 NULL array(0) { }
Output for 4.3.2 - 5.0.3
Warning: session_start(): Cannot send session cookie - headers already sent in /in/ZZB0I on line 2 Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at /in/ZZB0I:2) in /in/ZZB0I on line 2 Notice: Undefined variable: _SESSION in /in/ZZB0I on line 6 NULL array(0) { }
Output for 4.3.0 - 4.3.1
Warning: session_start() [http://www.php.net/function.session-start]: Cannot send session cookie - headers already sent in /in/ZZB0I on line 2 Warning: session_start() [http://www.php.net/function.session-start]: Cannot send session cache limiter - headers already sent (output started at /in/ZZB0I:2) in /in/ZZB0I on line 2 Notice: Undefined variable: _SESSION in /in/ZZB0I on line 6 NULL array(0) { }