Question

Best practices question: Is there anything improper about creating a new object within another class method? I have a small example below:

public function export() {

$orders = new Orders($id);
$all_orders = $orders->get_all_orders();

  }

Answer 1

The example you gave is perfectly acceptable.

If for example, you were instantiating the same object in all of your methods then you could store the object as a property instead.

Example: The Orders object is instantiated in the constructor and stored as a property.

class Something
{    
    protected $orders;

    public function __construct($id)
    {
        $this->orders = new Orders($id);
    }

    public function export()
    {

        // use $this->orders to access the Orders object
        $all_orders = $this->orders->get_all_orders();
    }

}