get doc ids in collection code example

Example 1: get one document based on id in firestore

//retrieve one document and save it to userDetails
const [userDetails, setUserDetails] = useState('')
db.collection('users').doc(id).get()
        .then(snapshot => setUserDetails(snapshot.data()))

Example 2: how to get firebase document id angular

.valueChanges({ idField: 'propertyId' });