An n-dimensional array is used to calculate the number of elements in each dimension (each element in each dimension may be an array or scalar)

You can also use $ eartharray ({code...}) without code, or return 3, 5, and 14 without code.
For example
$ Earth = array (

'asia'=>array(    'china'=>array(        'beijing',        'shanghai',        'tianjin',        'hangzhou'    ),    'japan'=>array(        'tokyo',        'hokkaido',        'nagasaki'    )),'europe'=>array(    'france'=>array(        'paris',        'lyon'    ),    'spain'=>array(        'madrid',        'barcelona',        'sevilla'    )),'australia'=>array(    'australia'=>array(        'sydney',        'melbourne'    ))

);
Returns 3, 5, 14

Reply content:

You can do this without code or ideas.
For example
$ Earth = array (

'asia'=>array(    'china'=>array(        'beijing',        'shanghai',        'tianjin',        'hangzhou'    ),    'japan'=>array(        'tokyo',        'hokkaido',        'nagasaki'    )),'europe'=>array(    'france'=>array(        'paris',        'lyon'    ),    'spain'=>array(        'madrid',        'barcelona',        'sevilla'    )),'australia'=>array(    'australia'=>array(        'sydney',        'melbourne'    ))

);
Returns 3, 5, 14

I think you should only use recursion to make such statistics.

// $ Array: array to be counted. $ I indicates the dimension. $ count indicates the upper-layer function count_array ($ array, $ I = 1, $ count = array ()) {$ n = 0; if (isset ($ count [$ I]) {$ n = $ count [$ I];} $ count [$ I] = count ($ array) + $ n; $ I + = 1; foreach ($ array as $ item) {if (is_array ($ item )) {$ count = sp_arr ($ item, $ I, $ count) ;}} return $ count ;} $ array = array ('a' => array ('B' => 'C', 'D' => 'e ', 'F' => 'G',), 'H' => array ('I' => array ('J' => 'K ', 'L' => 'm', 'n' => array ('O' => 'P', 'q' => 'r ')))); $ count = count_array ($ array); var_dump ($ count); // result:/*** array (size = 4) * 1 => int 2*2 => int 4*3 => int 3*4 => int 2 */

Okay, I write a loop (it can be optimized and optimized by myself, because I am not very familiar with PHP)
In short, it is a breadth-first search (a queue with a slight optimization, if changed to a stack, it is a depth-first)

function count_array($array) {    $count = array();    $level = 0;        $tfifo = $array;        do{    $fifo = $tfifo;    $tfifo = array();    $count[$level] = 0;    foreach($fifo as $item){        $count[$level]++;        if(is_array($item)) {            foreach($item as $subitem){            $tfifo[] = $subitem;        }        }    }    $level++;    }while(count($tfifo)>0);    return $count;}

Arr {x} {y} [z]
Isn't the number of elements in the third dimension arr {x} {y}. length?
And so on?
Or is there an error in my understanding of your problem?

Not listed in brackets ,,,

$ Num = array (); function get_num ($ fat, $ num) {$ num [] = count ($ fat); $ sun = array (); foreach ($ fat as $ key = >$ value) {if (is_array ($ value) {foreach ($ value as $ k => $ v) {$ sun [] = $ v ;}}if ($ sun) {return get_num ($ sun, $ num) ;}return $ num ;} // var_dump (get_num ($ arr, $ fat)