json_decode() when there are multiple results - php

Question

I am trying to get my head around how I can get the SKU's (and additionally the ID) from json results. I can do this when there are just one set of values called SKU but I have spent hours trying to understand how to do this when there are multiple.
Below is a sample of what my json returns
{
"variants": [
{
"id": 6852445,
"name": "Ikan VK7i 7\" LCD Monitor for Sony L with sun hood",
"sku": "VK7i-S-SHX7",
},
{
"id": 6852388,
"name": "ikan Flyweight DSLR",
"sku": "ELE-FLWDSLR",
},
{
"id": 6838367,
"name": "Atomos Sun Hood for Ninja/Ninja-2 including Double Adapter",
"sku": "AO-ATOMSUN001",
},
]
}
I currently have this code (I am a newbee). What I am trying to do is make the sku and the ID both variables but I am just hitting a brick wall. Currently I get
Warning: Invalid argument supplied for foreach() in /home/pearingc/public_html/returns/test2.php on line 15
<?php
$context = stream_context_create(array(
'http' => array(
'header' => "Authorization: Bearer *my token details* ")
)
);
$url = "http://api.tradegecko.com/variants/";
$data = file_get_contents($url, false, $context);
$json = json_decode($data, true);
$product = $json{'variant'}->{'sku'};
foreach ($product['sku'] as $sku) {
print $sku;
}
?>
Edit: This is what the var_dump($json); gives me
object(stdClass)#1 (2) { ["variants"]=> array(100) { [0]=> object(stdClass)#2 (42) { ["id"]=> int(6852445) ["created_at"]=> string(24) "2015-05-20T10:09:09.629Z" ["updated_at"]=> string(24) "2015-05-20T10:10:40.351Z" ["product_id"]=> int(1991122) ["default_ledger_account_id"]=> NULL ["buy_price"]=> string(5) "404.0" ["committed_stock"]=> string(1) "0" ["incoming_stock"]=> string(1) "0" ["composite"]=> bool(true) ["description"]=> NULL ["is_online"]=> bool(false) ["keep_selling"]=> bool(false) ["last_cost_price"]=> NULL ["manage_stock"]=> bool(true) ["max_online"]=> NULL ["moving_average_cost"]=> NULL ["name"]=> string(49) "Ikan VK7i 7" LCD Monitor for Sony L with sun hood" ["online_ordering"]=> bool(false) ["opt1"]=> NULL ["opt2"]=> NULL ["opt3"]=> NULL ["position"]=> int(6) ["product_name"]=> string(33) "ikan 7" HDMI Monitor W/ IPS Panel" ["product_status"]=> string(6) "active" ["product_type"]=> string(8) "Monitors" ["retail_price"]=> NULL ["sellable"]=> bool(true) ["sku"]=> string(11) "VK7i-S-SHX7" ["status"]=> string(6) "active" ["stock_on_hand"]=> string(1) "0" ["supplier_code"]=> NULL ["taxable"]=> bool(true) ["upc"]=> NULL ["weight"]=> NULL ["wholesale_price"]=> NULL ["image_ids"]=> array(0) { } ["variant_prices"]=> array(1) { [0]=> object(stdClass)#3 (2) { ["price_list_id"]=> string(3) "buy" ["value"]=> string(5) "404.0" } } ["locations"]=> array(1) { [0]=> object(stdClass)#4 (6) { ["location_id"]=> int(16377) ["stock_on_hand"]=> string(1) "0" ["committed"]=> string(1) "0" ["incoming"]=> NULL ["bin_location"]=> NULL ["reorder_point"]=> NULL } } ["prices"]=> object(stdClass)#5 (1) { ["buy"]=> string(5) "404.0" } ["stock_levels"]=> object(stdClass)#6 (1) { ["16377"]=> string(3) "0.0" } ["committed_stock_levels"]=> object(stdClass)#7 (1) { ["16377"]=> string(3) "0.0" } ["incoming_stock_levels"]=> object(stdClass)#8 (0) { } }

Answer 1

I think You have malformed JSON. Note: I removed commas after sku. Try this :
$data = '{
"variants": [
{
"id": 6852445,
"name": "Ikan VK7i 7\" LCD Monitor for Sony L with sun hood",
"sku": "VK7i-S-SHX7"
},
{
"id": 6852388,
"name": "ikan Flyweight DSLR",
"sku": "ELE-FLWDSLR"
},
{
"id": 6838367,
"name": "Atomos Sun Hood for Ninja/Ninja-2 including Double Adapter",
"sku": "AO-ATOMSUN001"
}
]
}';
And after that:
$json = json_decode($data);
foreach ($json->variants as $row) {
print $row->sku;
}

Answer 2

<?php
$json = '{
"variants": [
{
"id": 6852445,
"name": "Ikan VK7i 7\" LCD Monitor for Sony L with sun hood",
"sku": "VK7i-S-SHX7"
},
{
"id": 6852388,
"name": "ikan Flyweight DSLR",
"sku": "ELE-FLWDSLR"
},
{
"id": 6838367,
"name": "Atomos Sun Hood for Ninja/Ninja-2 including Double Adapter",
"sku": "AO-ATOMSUN001"
}
]
}';
foreach(json_decode($json,true)['variants'] as $item) {
echo $item['sku'] . "<br />";
}
?>
Condensed it a little bit.