$type_count = 0;
foreach($arr as $v) {
    if(array_key_exists('type', $v)) $type_count++;
}

You can use:

count($array, COUNT_RECURSIVE);

Count number of leaves in nested array tree

This can be done with a simple iteration:

$counts = array();
foreach ($array as subarr) {
  // Add to the current group count if it exists
  if (isset($counts[$subarr['group']]) {
    $counts[$subarr['group']]++;
  }
  // or initialize to 1 if it doesn't exist
  else $counts[$subarr['group']] = 1;

  // Or the ternary one-liner version 
  // instead of the preceding if/else block
  $counts[$subarr['group']] = isset($counts[$subarr['group']]) ? $counts[$subarr['group']]++ : 1;
}

###Update for PHP 5.5

In PHP 5.5, which has added the array_column() function to aggregate an inner key from a 2D array, this can be simplified to:

$counts = array_count_values(array_flip(array_column($array, 'group')));

You should be able to simply

echo count(array_column($meeting, 'person'));

Demo on 3v4l.org

A bit late but this is a clean way to write it.

$totalTickets = array_sum(array_map("count", $tickets));

Assuming $tickets is your multi-dimensional array.

I've expanded the code to give an explained example because array_map might be new to some

$tickets = array(
    "type1" => array(
        "ticket1" => array(),
        "ticket2" => array(),
        "ticket3" => array(),
    ),
    "type2" => array(
        "ticket4" => array(),
        "ticket5" => array(),
        "ticket6" => array(),
        "ticket7" => array(),
    ),
    "type3" => array(
        "ticket8" => array()
    )
);

// First we map count over every first level item in the array
// giving us the total number of tickets for each type.
$typeTotals = array_map("count", $tickets);

// print_r($typeTotals);
// $type_totals --> Array (
//                       [type1] => 3,
//                       [type2] => 4,
//                       [type3] => 1 
//                  )

//Then we sum the values of each of these
$totalTickets = array_sum($typeTotals);

print($totalTickets);
// $totalTickets --> 8

So because we don't care about the intermediate result of each type we can feed the result into array_sum

$totalTickets = array_sum(array_map("count", $tickets));

Create a results array. Then iterate the outer array, and inside the loop iterate the child array and increment the results array accordingly:

$data = array(
    "barack obama"  =>  array(0,50,150,250,600,900,45,150,1050),
    "tom jones"     =>  array(80,120,150,75,250,80,1100,1900),
    "bob mugabe"    =>  array(50,120,10,0,250,900,600,45,1000,1010),
);    

$results = array(); // create an empty array to store our results
foreach ( $data as $item ): // loop the outer array
    foreach ( $item as $key => $value ): // loop the inner array
        if ( array_key_exists($value,$results) ){ // check if value is already in results, if not set to 1, otherwise increment
            $results[$value] = $results[$value] + 1;
        } else { 
            $results[$value] = 1;
        }

    endforeach;
endforeach;

// show our results array
print "<pre>";
print_r($results);

To count the keys in a two dimensional array with a search I would do this -

function countKeys($array,$search){
    $key_count = array(); // new array
    foreach($array as $record) {  
        $keys = array_keys($record);
        foreach($keys as $key){
            if($key == $search){ // check against the search term
                array_push($key_count, $key); // add the key to the new array
            }
        }
    }
    return count($key_count); // just count the new array
}
echo countKeys($records, 'last_name');

EXAMPLE

array_keys() count()

Use $sum as array and get correct value of multiarray:

$sum = array(
       'clicks' => 0,
       'views' => 0
       );

foreach ($data as $id => $value) {
    $sum['clicks'] += $value['clicks'];
    $sum['views'] += $value['views'];
}

dd($sum);

With the count function.

$size = count($arr[0]);

Just one line more:

$args = array_column($arr, 'Fulfill');
$sum = array_sum($args)/count($args);

You can simply use array_count_values along with call_user_func_array like as

array_count_values(call_user_func_array('array_merge', $array));