Grouped Array data - php

Question

I'm trying to figure out how to get data from the following data structure. I managed to group a flat array into the following array, but am finding it difficult to find the proper resources to explain how to get the data out. I'm looking to get the count of the items in each group. Then i'd like to print the ids from the inner array...
array (
'grinds' =>
array (
0 =>
array (
'id' => 16562,
'slug' => 'grinds',
),
1 =>
array (
'id' => 16561,
'slug' => 'grinds',
),
),
'online-grinds' =>
array (
0 =>
array (
'id' => 16566,
'slug' => 'online-grinds',
),
),
)

Answer 1

$my_array1 = array(
'grinds' =>
array(
0 =>
array(
'id' => 16562,
'slug' => 'grinds',
),
1 =>
array(
'id' => 16561,
'slug' => 'grinds',
),
),
'online-grinds' =>
array(
0 =>
array(
'id' => 16566,
'slug' => 'online-grinds',
),
),
);
get counts:
$counts = array();
foreach ($my_array1 as $key => $val) {
$counts[$key] = count($val);
}
var_dump($counts);
yields:
array(2) {
["grinds"]=>
int(2)
["online-grinds"]=>
int(1)
}
get inner ids:
$innerids = array();
foreach ($my_array1 as $key => $val) {
foreach ($val as $key2 => $val2) {
$innerids[] = $val2['id'];
}
}
var_dump($innerids);
yields:
array(3) {
[0]=>
int(16562)
[1]=>
int(16561)
[2]=>
int(16566)
}

Answer 2

You could use array_map and then for every item use array_column and specifing the field name and then use array_count_values to count the unique values.
Then combine those in an array and use the existing key again as the key for then new array.
$arrays = array_map(function($x) {
return [
array_count_values(array_column($x, 'id')),
array_count_values(array_column($x, 'slug'))
];
}, $arrays);
print_r($arrays);
Result
Array
(
[grinds] => Array
(
[0] => Array
(
[16562] => 1
[16561] => 1
)
[1] => Array
(
[grinds] => 2
)
)
[online-grinds] => Array
(
[0] => Array
(
[16566] => 1
)
[1] => Array
(
[online-grinds] => 1
)
)
)
Demo