PHP with JSON decode and steam api - php

Question

I am new to php at this stage, same about openID libraries. I want to make a website for Steam users so I need to display their inventory. I've downloaded some example things which most thing written but I still need something else. As a training I took a something else than inventory, but similiar. Didn't make it so I hope that you can help me.
That's a example what I was looking at while trying to decode another data.
{
"response": {
"players": [
{
"steamid": "76hidden",
"communityvisibilitystate": 3,
"profilestate": 1
}
]
}
}
And code in PHP looks like
$url2 = file_get_contents("url");
$content = json_decode($url2, true);
$_SESSION['steam_steamid'] = $content['response']['players'][0]['steamid'];
$steamprofile['steamid'] = $_SESSION['steam_steamid'];
And this one above is working well. Could you please explain me why there is 0 between "steamid" and "players"? Also it looks like the session name matters, am I right? I was doing some tests and when I changed the name session it didn't work.
So here's what I am working on
JSON code:
{
"friendslist": {
"friends": [
{
"steamid": "765hidden",
"relationship": "friend",
"friend_since": 1428495026
},
{
"steamid": "764hidden",
"relationship": "friend",
"friend_since": 1355599210
},
{
"steamid": "764hidden",
"relationship": "friend",
"friend_since": 1423504205
},
much more friends
]
}
}
So I want to get the steamid and I got no idea how to get it. I've tried to get relationship as steamID is already used above:
$url3 = file_get_contents("url2");
$content2 = json_decode($url3, true);
$_SESSION['steam_relationship'] = $content2['friendslist']['friends'][0]['relationship'];
$steamfriends['friend'] = $_SESSION['steam_relationship'];
And of course echo $steamfriend['friend'] is not working. I see that person who made these PHP files already know what are the session names (if they need to be right to work). Any ideas where can I find it?
I feel really ashamed that I can't figure it myself.
Regards.

Answer 1

The first JSON
{
"response": {
"players": [
{
"communityvisibilitystate": 3,
"profilestate": 1,
"steamid": "76hidden"
}
]
}
}
translates to this PHP array
$content = array(
"response" => array(
"players" => array(
array(
"communityvisibilitystate" => 3,
"profilestate" => 1,
"steamid" => "76hidden"
)
)
)
)
The players is an array of arrays (hash arrays), so to access the first player you need to use index number ($content["response"]["players"][0]["steamid"]) even if there is just one player in the players array.
To get all steamids from the second array, you just need to run a simple foreach:
$friendIds = array();
foreach ($content2["friendslists"]["friends"] as $friend) {
$friendIds[] = $friend["steamid"];
}
# array("764hidden", "764hidden", "764hidden")
var_export($friendIds);

Answer 2

When the JSON is created they use a method similar to this:
foreach ($record as $response){
$content['response']['players'][] = $response;
}
Where $player may be an array with multiple values, or not.
It just makes it easier to create the JSON.
First make the JSON an array:
$array = json_decode($json,true)
Then get it like this:
session_start();
$_SESSION['relationship'] = $array['friendslist']['friends'][0]['relationship'];
$_SESSION['steamid'] = $array['friendslist']['friends'][0]['steamid'];
$_SESSION['steam_relationship'] = $array['friendslist']['friends'][0]['steam_relationship'];
The typical way to get all the player info:
foreach ($array['friendslist']['friends'] as $key => $value){
$steamid = $value['steamid'];
$relationship = $value['relationship'];
$friend_since = $value['friend_since'];
// do what need to be done here.
}