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<?php $header = array('test'); if (isset($header[0]['class']) && key_exists('class', $header[0])) { echo 'set'; } else { echo 'not set'; }
Output for 5.0.0 - 5.0.2, 5.4.0 - 5.4.45, 5.5.24 - 5.5.35, 5.6.8 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.25, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.18, 8.3.0 - 8.3.6
not set
Output for 5.3.0 - 5.3.29
Warning: key_exists() expects parameter 2 to be array, string given in /in/kfjgY on line 3 not set
Output for 4.3.2 - 4.3.11, 4.4.0 - 4.4.9, 5.0.3 - 5.0.5, 5.1.0 - 5.1.6, 5.2.0 - 5.2.17
Warning: key_exists(): The second argument should be either an array or an object in /in/kfjgY on line 3 not set
Output for 4.3.0 - 4.3.1
Warning: key_exists() [http://www.php.net/function.key-exists]: The second argument should be either an array or an object in /in/kfjgY on line 3 not set

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