попробуйте, надеюсь, это поможет
<!DOCTYPE html>
<html>
<body>
<h2>Convert a JavaScript object into a JSON string, and send it to the server.</h2>
<script>
var myObj = {
"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"
}
}
}
}
console.log(Object.keys(myObj.quiz))
</script>
</body>
</html>