Question

EDIT: Thanks everyone. I didn’t even notice it was private lol, so I changed them from private to public, now it should be accessible… question now is how can I access the value of say ‘backpackPosition’? thanks again!

TF2Inventory Object
(
[fetchDate] => 123456123
[items] => Array
    (
        [60] => TF2Item Object
            (
                [equipped] => Array
                    (
                        [scout] => 1
                        [sniper] => 1
                        [soldier] => 1
                        [demoman] => 1
                        [medic] => 1
                        [heavy] => 1
                        [pyro] => 1
                        [spy] => 1
                    )

                [attributes] => Array
                    (
                        [0] => stdClass Object
                            (
                                [name] => custom employee number
                                [class] => set_employee_number
                                [value] => 0
                            )

                        [1] => stdClass Object
                            (
                                [name] => cannot trade
                                [class] => cannot_trade
                                [value] => 1
                            )

                    )

                [backpackPosition] => 61
                [className] => tf_wearable
                [count] => 1
                [defindex] => 170
                [id] => 535518002
                [level] => 20
                [name] => Primeval Warrior
                [quality] => unique
                [slot] => misc
                [tradeable] => 
                [type] => Badge
            )

        [43] => TF2Item Object
            (
                [equipped] => Array
                    (
                        [scout] => 0
                        [sniper] => 0
                        [soldier] => 0
                        [demoman] => 0
                        [medic] => 0
                        [heavy] => 0
                        [pyro] => 0
                        [spy] => 0
                    )

                [attributes] => Array
                    (
                        [0] => stdClass Object
                            (
                                [name] => cannot trade
                                [class] => cannot_trade
                                [value] => 1
                            )

                    )

                [backpackPosition] => 44
                [className] => tf_wearable
                [count] => 1
                [defindex] => 471
                [id] => 535518003
                [level] => 50
                [name] => Proof of Purchase
                [quality] => unique
                [slot] => head
                [tradeable] => 
                [type] => Hat
            )

        [42] => TF2Item Object
            (
                [equipped] => Array
                    (
                        [scout] => 1
                        [sniper] => 1
                        [soldier] => 1
                        [demoman] => 1
                        [medic] => 1
                        [heavy] => 1
                        [pyro] => 1
                        [spy] => 1
                    )

                [attributes] => 
                [backpackPosition] => 43
                [className] => tf_wearable
                [count] => 1
                [defindex] => 278
                [id] => 541628464
                [level] => 31
                [name] => Horseless Headless Horsemann's Head
                [quality] => unique
                [slot] => head
                [tradeable] => 
                [type] => Hat
            )

        [59] => TF2Item Object
            (
                [equipped] => Array
                    (
                        [scout] => 0
                        [sniper] => 0
                        [soldier] => 0
                        [demoman] => 0
                        [medic] => 0
                        [heavy] => 0
                        [pyro] => 0
                        [spy] => 0
                    )

                [attributes] => Array
                    (
                        [0] => stdClass Object
                            (
                                [name] => cannot trade
                                [class] => cannot_trade
                                [value] => 1
                            )

                    )

                [backpackPosition] => 60
                [className] => tf_wearable
                [count] => 1
                [defindex] => 115
                [id] => 548155039
                [level] => 10
                [name] => Mildly Disturbing Halloween Mask
                [quality] => unique
                [slot] => head
                [tradeable] => 
                [type] => Holiday Hat
            )

Answer 1

Private members are just that – private. Only the class they belong to can access them. If you want to be able to retrieve their values, you need to either make them protected (and thus available to parent and children classes) or public (available to all classes). Another option is to write some getters, functions that look like

public function get_slot() {
    return $this->slot;
}

or use the __get() magic function to make a general getter that looks like

public function __get($name) {
    return $this->$name;
}

More info can be found in the documentation at http://php.net/manual/en/language.oop5.visibility.php