Description:
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---
https://www.php.net/manual/en/language.types.array.php
---
in the php docment  about Arrays it is said "Converting NULL to an array results in an empty array." this is absolutely wrong .in fact if execute array(NULL),the result is not an empty array the array key will be 0 the array value will be NULL

Test script:
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public function arrTest(){
    $a   = NULL;
    $arr = array($a);
    foreach ($arr as $key => $value) {
        var_dump($key);    // 0
        var_dump($value);  // NULL
    }
    var_dump(count($arr)); // 1
    exit;
}