Im new to PHP, I have a json file that contains several 'events' objects that look like the following. This is one 'event':
"2252182": {
    "id"                : "2252182",
    "name"              : "Arsenal-Everton",
    "tournament_stageFK": "844714",
    "startdate"         : "2017-05-21T14:00:00+00:00",
    "status_type"       : "notstarted",
    "property"          : {},
    "event_participants": {
        "7297686": {
            "id"           : "7297686",
            "number"       : "1",
            "participantFK": "9825",
            "eventFK"      : "2252182",
            "n"            : "0",
            "ut"           : "2016-06-15T08:05:33+00:00",
            "result"       : {},
            "participant"  : {
                "id"          : "9825",
                "name"        : "Arsenal",
                "gender"      : "male",
                "type"        : "team",
                "countryFK"   : "2",
                "n"           : "2",
                "ut"          : "2016-09-15T10:44:36+00:00",
                "country_name": "England"
            }
        },
        "7297687": {
            "id"           : "7297687",
            "number"       : "2",
            "participantFK": "8668",
            "eventFK"      : "2252182",
            "n"            : "0",
            "ut"           : "2016-06-15T08:05:33+00:00",
            "result"       : {
                "24255418": {
                    "id"                  : "24255418",
                    "event_participantsFK": "7297687",
                    "result_typeFK"       : "1",
                    "result_code"         : "ordinarytime",
                    "value"               : "0",
                    "n"                   : "0",
                    "ut"                  : "2016-06-15T08:05:33+00:00"
                },
                "24255420": {
                    "id"                  : "24255420",
                    "event_participantsFK": "7297687",
                    "result_typeFK"       : "6",
                    "result_code"         : "runningscore",
                    "value"               : "0",
                    "n"                   : "0",
                    "ut"                  : "2016-06-15T08:05:33+00:00"
                }
            },
            "participant"  : {
                "id"          : "8668",
                "name"        : "Everton",
                "gender"      : "male",
                "type"        : "team",
                "countryFK"   : "2",
                "n"           : "2",
                "ut"          : "2016-09-15T10:45:47+00:00",
                "country_name": "England"
            }
        }
    }
}
I have used php to decode into a php array, but the event_participants objects are not being converted into arrays, or if they are, when I try and access $fixture['event_participants'][0] I am getting Message: Undefined offset: 0 error. My code is below:
$json = json_decode(file_get_contents('assets/json/fixtures.json'),true);
foreach ($json['events'] as $fixture)
    {
        $tmp = array();
        $tmp['group_id']    = $fixture['tournament_stageFK'];
        $tmp['group_league'] = $fixture['tournament_stage_name'];
        $tmp['fixture_id']      = $fixture['id'];
        $tmp['fixture_name']    = $fixture['name'];
        $tmp['fixture_date']    = $fixture['startdate'];
        $tmp['fixture_status']  = $fixture['status_type'];
        $tmp['event_participants'] = $fixture['event_participants'];
        if (isset($fixture['event_participants'])) {
            print_r($fixture['event_participants'][0]);
        }
    }
If I do $fixture['event_participants'][0] I expect to receive: 
       {
            "id"           : "7297686",
            "number"       : "1",
            "participantFK": "9825",
            "eventFK"      : "2252182",
            "n"            : "0",
            "ut"           : "2016-06-15T08:05:33+00:00",
            "result"       : {},
            "participant"  : {
                "id"          : "9825",
                "name"        : "Arsenal",
                "gender"      : "male",
                "type"        : "team",
                "countryFK"   : "2",
                "n"           : "2",
                "ut"          : "2016-09-15T10:44:36+00:00",
                "country_name": "England"
            }
        }
So I answered my own query - array_values solved my issue:
        if (isset($fixture['event_participants'])) {
            $num = array_values($fixture['event_participants']);
            $tmp['participant_1_id'] = $num[0]['participant']['id'];
            $tmp['participant_1_name'] = $num[0]['participant']['name'];
            $tmp['participant_2_id'] = $num[1]['participant']['id'];
            $tmp['participant_2_name'] = $num[1]['participant']['name'];
        }
