如何从 PHP 对象数组中检索项目？

Question

I want to retrieve quantities from this array.

  invoice Object
    (
    [data:private] => Array
    (
    [i_status] => pend
    [i_title] => 500 HLCoins , 500 HLCoins x8
    [i_member] => 1
    [i_items] => Array
    (
    [0] => Array
    (
    [act] => new
    [app] => nexus
    [type] => product
    [cost] => 0
    [tax] => 0
    [renew_term] => 0
    [renew_units] =>
    [renew_cost] => 0
    [quantity] => 1
    [physical] =>
    [shipping] => Array
    (
    )
    [weight] => 0
    [itemName] => 500 HLCoins
    [itemID] => 3
    [cfields] => Array
    (
    )
    [extra] =>
    [opt_id] => 0
    [associated] =>
    [assocBought] =>
    [groupRenewals] => 0
    [methods] => Array
    (
    )
    [k] => 0
    [_tax] => 0
    )
    [1] => Array
    (
    [act] => new
    [app] => nexus
    [type] => product
    [cost] => 0
    [tax] => 0
    [renew_term] => 0
    [renew_units] =>
    [renew_cost] => 0
    [quantity] => 8
    [physical] =>
    [shipping] => Array
    (
    )
    [weight] => 0
    [itemName] => 500 HLCoins
    [itemID] => 3
    [cfields] => Array
    (
    )
    [opt_id] => 0
    [groupRenewals] => 0
    [methods] => Array
    (
    )
    [_tax] => 0
    )
    )
    [i_total] => 0
    [i_date] => 1347217384
    [i_return_uri] =>
    [i_paid] => 0
    [i_status_extra] => a:1:{s:4:"type";s:4:"zero";}
    [i_discount] => 0
    [i_temp] =>
    [i_ordersteps] => 0
    [i_noreminder] => 1
    [i_renewal_ids] => Array
    (
    )
    [i_po] =>
    [i_notes] =>
    [i_shipaddress] =>
    [i_id] => 229
    )


        [takeAction] => 1
    )

I've tried a bunch of codes like $invoice->quantity, $invoice[1]->quantity, $this->$invoice->quantity, but none of them seem to display.

It still does not display at all, I tried to print_r and that is the array it gave me.

Answer 1

All the variables are private which means you cannot access them from outside the object. Check out the class definition for the invoice class. There should be some function to get the quantities from the object, or else you could add such a feature to the class.

The whole point of this is separation of concerns. The class may change in the future and possibly not use the same structure, therefore you should use object functions to access the properties, do not access them directly as variables.

You can read more on this subject in the manual or in a book about object-oriented programming.

Answer 2

Seems like all the data is in a private property. You cannot access it from outside directly.

Read the documentation for the class. It should have some method you can call, like getQuantity() , that'll get you the data. It depends on how the class was written and how it is supposed to be used.