php access object keys/values - php

Question

I was wondering how I could go about accessing values within an object, such as 'backpackPosition'? I'm guessing I would have to put it in some kind of foreach loop, but I have no idea how to get the values.
TF2Inventory Object
(
[fetchDate] => 1234541231
[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

foreach($inventory_object->items as $item)
{
$item->backpackPosition;
}