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run code in 300+ PHP versions simultaneously
<?php $corban_notice = false; if (!function_exists('cd')) { function cd($var) { global $corban_notice; if (!isset($var)) { if ($corban_notice) { echo 'cd: Variable is not set'.PHP_EOL; $corban_notice = false; } else { echo 'cd: Variable is NULL'.PHP_EOL; } } } } function corban_error_handler($errno , $errstr, $errfile, $errline) { global $corban_notice; if ( version_compare(PHP_VERSION, '5.0.0', '>=') ) { $file = new SplFileObject($errfile); $file->seek($errline-1); $c = substr(trim($file->current()), 0, 3); if ($c=='cd(' || $c=='cd ') { $corban_notice = true; } } return false; } set_error_handler ('corban_error_handler', E_NOTICE); var_dump($a); $b = null; cd($a); cd($b);

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38.34 ms | 402 KiB | 5 Q