Laravel：array_push 在 collection->each() 迭代器中不起作用

Question

I have grouped collection and I iterate it using each() function.Inside the each function I want to add element to some array.But it is not working.Any idea?

$dataSet1 = [];

$appointments = [
         ['department' => 'finance', 'product' => 'Chair'],
         ['department' => 'marketing', 'product' => 'Bookcase'],
         ['department' => 'finance', 'product' => 'Desk'],
]; 
$groupData = collect($appointments)->groupBy('department');

$groupData->each(function ($item, $key) {
   Log::info($key); //Show correct output in log
   array_push($dataSet1, $key); //ERROR
   array_push($dataSet1, 'A');//ERROR
});

Laravel version: 8.35.1

Answer 1

You need to pass the array to the function with use :

$groupData->each(function ($item, $key) use (&$dataSet1) {
   Log::info($key); //Show correct output in log
   array_push($dataSet1, $key); //ERROR
   array_push($dataSet1, 'A');//ERROR
});

Pass-by-reference ( & ) is needed as long as $dataSet1 is not an object instance.