PHP converts a one-dimensional array into a two-dimensional array

$fruit = array('a' => 'apple', 'b' => 'banana', 'c' => 'cranberry');
 
$fruit = array(
    array('key'=>'a', 'val'=>'apple'), 
    array('key'=>'b', 'val'=> 'banana'), 
    array('key'=>'c', 'val'=> 'cranberry')
);
 
$fruit = array('a' => 'apple', 'b' => 'banana', 'c' => 'cranberry');
 
$tmp = array();
reset($fruit);
while (list($key, $val) = each($fruit)) {
    $tmp[] = array('key'=>$key,'val'=>$val);
}
print_r($tmp);