$arr = array('key1' => 'php', 'key2' => 'java', 'key3' => 'c++', 'key4' => 'python');
$val = "c++";
$arr= array_filter($arr, function($element) use ($val) { return($element != $val); });
print_r($arr);
/*
run:
Array ( [key1] => php [key2] => java [key4] => python )
*/