Laravel：没有未使用的参数，方法不起作用

Question

I have a method remove() which has parameter $item, but it is not being used inside of it. PhpStorm has it grayed out and says that parameter $item is not being used anywhere. But if I remove it I get this error:

ErrorException in Cart.php line 51:
Illegal offset type
in Cart.php line 51
at HandleExceptions->handleError('2', 'Illegal offset type', 'C:\wamp64\www\laravel\app\Cart.php', '51', array('id' => object(Product))) in Cart.php line 51
at Cart->remove(object(Product), '1') in ProductController.php line 65
at ProductController->removeFromCart('1')
at call_user_func_array(array(object(ProductController), 'removeFromCart'), array('id' => '1')) in compiled.php line 9399
at Controller->callAction('removeFromCart', array('id' => '1')) in compiled.php line 9426
at ControllerDispatcher->dispatch(object(Route), object(ProductController), 'removeFromCart') in compiled.php line 8484
at Route->runController() in compiled.php line 8465
at Route->run(object(Request)) in compiled.php line 8174

Cart.php:

/**
 * Remove an item from cart
 *
 * @param $item
 * @param $id
 */
public function remove($item, $id)
{
    $this->totalQty -= $this->items[$id]['qty']; // Line 51
    $this->totalPrice -= $this->items[$id]['price'] * $this->items[$id]['qty'];
    unset($this->items[$id]);
}

Works fine if I leave it there, but why it doesn't when I remove it?

Answer 1

When you update the method signature you have to update every instance of that method being called to reflect the new parameters. In your ProductController on line 65 it's still using the old method signature (with both item and id). To fix it update the method call in your controller to just use $id.