How do i get key in php json data

I managed to get all the data in loops one by one. But I only want to get the 2 questions inside the ‘maths’ object and when I try other methods I get different errors.
Ex: Cannot use object of type stdClass as array

JSON:

{
"quiz": {
    "sport": {
        "q1": {
            "question": "Which one is correct team name in NBA?",
            "options": [
                "New York Bulls",
                "Los Angeles Kings",
                "Golden State Warriros",
                "Huston Rocket"
            ],
            "answer": "Huston Rocket"
        }
    },
    "maths": {
        "q1": {
            "question": "5 + 7 = ?",
            "options": [
                "10",
                "11",
                "12",
                "13"
            ],
            "answer": "12"
        },
        "q2": {
            "question": "12 - 8 = ?",
            "options": [
                "1",
                "2",
                "3",
                "4"
            ],
            "answer": "4"
        }
    }
}

}

PHP Codes:

$jsonFile = json_decode(file_get_contents('example_2.json', true));
function getMathQuestions($jsonFile) {
    foreach($jsonFile as $val) {
        if(is_object($val)) {
            getMathQuestions($val);
        } else {
            if(is_array($val)) {
                getMathQuestions($val);
            } else {
                echo $val . "<br>";
            }
        }
    }
}
echo getMathQuestions($jsonFile);

>Solution :

You are missing json_decode parameter associative, if not specified you will get stdClass object instead of php array of data.

So change line:

$jsonFile = json_decode(file_get_contents('example_2.json', true));

to:

$jsonFile = json_decode(file_get_contents('example_2.json', true), true);