PHP change multidimensional array index in running foreach

I am trying to change multidimensional array index in running foreach:

$array = array(
    array("apple", "orange"),
    array("carrot", "potato")
    );

$counter = 0;

foreach($array[$counter] as &$item) {
    echo $item . " - ";
    $counter = 1;
}

I supposed, that output would be apple - carrot - potato -, because in first run it takes value from zero array and then in next runs values from first array.

However, the output is apple - orange -

I tried add "&" before variable $item, but i guess it is not what I am looking for.

Is there any way to do it?
Thank you

// Well, i will try to make it cleaner:
This foreach takes values from $array[0], but in run i want to change index to 1, so in next repeat it will take values from $array[1]

Is that clear enough?

Note: I do not know how many dimensions my array has.

My purpose of this is not to solve this exact case, all I need to know is if is it possible to change source of foreach loop in run:

My foreach

$counter = 0;
foreach($array[$counter] as $item) {
 echo $item . " - ";
}

is getting values from $array[0] right now. But inside it, I want to change $counter to 1, so next time it repeats, it will get values from $array[1]

$counter = 0;
foreach($array[$counter] as $item) {
 echo $item . " - ";
 $counter = 1;
}

I see, it is kind of hard to explain. This is how foreach should work:
Index of $array is $counter

First run
$array[0] -> as $item = apple
echo apple
wait, now counter changes to 1

Second run
$array[1] -> as $item = carrot
echo carrot

Third run
$array[1] -> as $item = potato
echo potato

END

I am really trying to make it clear as much as possible :D