{
 "kind": "youtube#channelListResponse",
 "etag": ""IHLB7Mi__JPvvG2zLQWAg8l36UU/cElfTza4UGHG8g6mYtCKSIOXxq0"",
 "pageInfo": {
  "totalResults": 1,
  "resultsPerPage": 5
 },
 "items": [
  {
   "kind": "youtube#channel",
   "etag": ""IHLB7Mi__JPvvG2zLQWAg8l36UU/EGw-f95GMJ7EnCAhVPMzL1JSykQ"",
   "id": "UCxAICW_LdkfFYwTqTHHE0vg",
   "statistics": {
    "viewCount": "107418936",
    "commentCount": "295",
    "subscriberCount": "428265",
    "hiddenSubscriberCount": false,
    "videoCount": "2270"
   }
  }
 ]
}

function test() {

    $url = "https://www.googleapis.com/youtube/v3/channels?part=statistics&forUsername=youtube&key={key}";
    $json = file_get_contents($url);
    $json_data = json_decode($json, true);
    echo $json_data["kind"];

}