how can sum count of parent child array-CodePudding

I have an array like this :

  $foo_array = array (
                         [3533] => 4 ,
                         
                         [353] =>  3 ,
                         
                         [351] =>  2 ,
                         
                         [35] =>   0 ,

                      );

this is an example array, it has many elements and it is dynamic from the database, but I want to say an example for you!

each key of an array has a parent like this, for example, 353 is the parent of 3533 and ...

Now I want to sum count of each parent from childrens count. the true result of count for key 35 must be 9, but I can't receive this result! I create foreach for this array and get all parents, after that plus count of that child to each parent of that but unfortunately get a bad result!

CodePudding user response：

This will give you an array with the parent as the index and the values of parent and children:

foreach($foo_array as $key => $val) {
    $result[$key] = array_intersect_key($foo_array, array_flip(preg_grep("/^$key/", array_keys($foo_array))));
}

Yields:

Array
(
    [3533] => Array
        (
            [3533] => 4
        )
    [353] => Array
        (
            [3533] => 4
            [353] => 3
        )
    [351] => Array
        (
            [351] => 2
        )
    [35] => Array
        (
            [3533] => 4
            [353] => 3
            [351] => 2
            [35] => 0
        )
)

So you can then access by parent:

echo array_sum($result[35]);

Or you could use $result[$key] = array_sum( . . . . . ); in the loop.

If you are only concerned with 35 for example then:

$key = 35;
$result = array_sum(array_intersect_key($foo_array, array_flip(preg_grep("/^$key/", array_keys($foo_array)))));