How to add elements to an empty array in PHP?

Hello everyone! I just started learning PHP and encountered a problem. I need to create an empty array and then dynamically add elements to it as I process data. For example, I have a list of items, and I want to collect only those with a price greater than 100 rubles.\n\nI wrote this code:\n\n```php\n$filtered_items = array();\nforeach ($items as $item) {\n if ($item['price'] > 100) {\n // Here I don't know how to correctly add an element\n }\n}\n```\n\nI tried writing `$filtered_items[] = $item;` and `array_push($filtered_items, $item);` — both options seem to work, but I don't understand the difference and which method is more correct. I also heard that you can use `array_push` with multiple elements at once. I'm also interested in whether it's possible to add elements not to the end, but to the beginning.