PHP - Nested Multidimensional Array Index counting

Question

If I have an array such as -

 Products ( 
      'ProductA' (
        'color' => 'red',
        'serial' => '1234a'
      ),

      'ProductB' (
        'color' => 'blue',
        'size' => 'large'
      ),

      'ProductC' (
        'color' => 'green',
        'serial' => '4567b'
      )
    )

is there a way to do something like -

count($products[*]['serial'])

I just need a count of all the products that have the 'serial' index.... using [] and [*] does not work.

Answer 1

$counter=0;
foreach($products as $product)
{
   if(isset($product["serial"]))
   $counter++;
}
echo $counter;

Answer 2

PHP >= 5.5.0 required:

$result = count(array_column($products, 'serial'));

Answer 3

You can use array_filter in conjucntion with isset:

$count = count(array_filter($array, function ($v) {
    return isset($v['serial']);
}));

Answer 4

Clear solution with array filter

      $products = array(
        'ProductA' => array(
                    'color' => 'red',
                    'serial' => '1234a'
                    ),
        'ProductB' => array(
                    'color' => 'red',
                    'size' => 'large'
                    ),
        'ProductC' => array(
                    'color' => 'red',
                    'serial' => '1234a'
                    ),
            );

    $nr = count(array_filter($products, function($arr) { return !empty($arr['serial']); }));
    echo $filtered;

Hope it helps