问如果我不知道键名，如何从另一个对象获取对象

EN

var obj = {
  "-LJFXZDI-O-qR572deOs": {
    "city": "almaty",
    "dob": "1995-08-06",
    "gender": "male",
    "height": "190",
    "userId": "LS1pYNjiIjRpSNV1xfXqngKAKjz2",
    "username": "aaaa",
    "weight": "80",
  },
}

keys = Object.keys(obj); // all keys of the outer object
myKey = keys[0]; // the unknown key of the inner object
innerObject = obj[myKey];
city = innerObject.city;

console.log(city);

const obj = {
  "-LJFXZDI-O-qR572deOs": {
    "city": "almaty",
    "dob": "1995-08-06",
    "gender": "male",
    "height": "190",
    "userId": "LS1pYNjiIjRpSNV1xfXqngKAKjz2",
    "username": "aaaa",
    "weight": "80",
  }
};
const key = Object.keys(obj)[0];
const city = obj[key].city;

console.log(key);
console.log(city);