saving data firestore code example

Example 1: javascript write to firebase

function writeUserData(userId, name, email, imageUrl) {
  firebase.database().ref('users/' + userId).set({
    username: name,
    email: email,
    profile_picture : imageUrl
  });
}

Example 2: firebase set vs update

firebase.database().ref().child('/posts/' + newPostKey)
        .set({ title: "New title", body: "This is the new body" });