Group and count nested arrays PHP - php

Question

I have an array that groups different items by item type. I am grouping the result by category_id field. What I want is the output to be
item1 = 3
item2 = 2
My array looks like this if I do a var_dump()
array(2) {
["item1"]=>
array(3) {
[0]=>
string(1) "3"
[2]=>
string(1) "5"
[4]=>
string(1) "7"
}
["item2"]=>
array(2) {
[1]=>
string(1) "4"
[3]=>
string(1) "6"
}
}
Here is the code I am using:
$items = Item::where('order_id','=',$payload["orderId"])->get();
$itemsGrouped = [];
$count = 0;
foreach($items as $item){
$itemsGrouped[$item->category_id][$count] = $item->id;
$count++;
}
foreach($itemsGrouped as $grp){
echo key($itemsGrouped).'='.count($grp).'<br>';
};
And here is what I am currently getting. The count is working but not the $itemsGrouped key. It is duplicated.
item2=3<br>item2=2<br>

Answer 1

Change your code as below
foreach($itemsGrouped as $key => $grp){
echo $key.'='.count($grp).'<br>';
};
In order to use key() function, you need to traverse the array using next/current function

Answer 2

foreach($itemsGrouped as $key => $grp){
echo $key.'='.count($grp).'<br>';
};
key() function returns the current element's key, which is defined by an array's internal pointer. Obviously it always points to the last element.

Answer 3

$myarray = "Your array";
$count = array(); // create an empty array
foreach($myarray as $arr) {
foreach($arr as $a) {
$key = array_keys($a);
$count[$key[0]]++;
}
}
print_r($count);