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<?php $arr = Array ( "chann_1" => 155.755, "chann_2" => 154.61, "chann_3" => 156.719, "chann_4" => 156.727, "chann_5" => 155.797, "chann_6" => 157.615, "chann_7" => 154.257, "chann_8" => 151.724, "chann_9" => 156.549, "chann_10" => 156.594, "chann_11" => 157.56, "chann_12" => 156.405 ); Arsort($arr); Var_dump($arr); $keys = array_keys($arr); Echo $keys[round(count($keys)/2)];
based on qXNrkQ
Output for 5.6.0 - 5.6.40, 7.0.0 - 7.0.33, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.27, 7.4.0 - 7.4.16, 8.0.0 - 8.0.3
array(12) { ["chann_6"]=> float(157.615) ["chann_11"]=> float(157.56) ["chann_4"]=> float(156.727) ["chann_3"]=> float(156.719) ["chann_10"]=> float(156.594) ["chann_9"]=> float(156.549) ["chann_12"]=> float(156.405) ["chann_5"]=> float(155.797) ["chann_1"]=> float(155.755) ["chann_2"]=> float(154.61) ["chann_7"]=> float(154.257) ["chann_8"]=> float(151.724) } chann_12