Get individual array Items - ios

Question

I am reading data from a firebase DB and storing it in a message object, How can I then access each element in that array? i.e how can I use the City string as I wish to assign that to a label. Same with each other element in the array.
firebaseDB.collection("user").document(key).collection("address").getDocuments() { (querySnapshot, err) in
if let err = err {
print("Error getting documents: \(err)")
}
else {
self.dataArr.removeAll()
for document in querySnapshot!.documents {
//print("\(document.documentID) => \(document.data())")
let msgdata = document.data() as! [String:Any]
var msgObj = Details()
if let city = msgdata["city"] as? String {
msgObj.city = city
}
if let country = msgdata["country"] as? String {
msgObj.country = country
}
if let county = msgdata["county"] as? String {
msgObj.county = county
}
if let lineOne = msgdata["lineOne"] as? String {
msgObj.lineOne = lineOne
}
if let lineTwo = msgdata["lineTwo"] as? String {
msgObj.lineTwo = lineTwo
}
if let postCode = msgdata["postCode"] as? String {
msgObj.postCode = postCode
}
self.dataArr.append(msgObj)
}
}
}
I will need to access each element as I have another function which will take each element and place it on a label in my ViewController
Something like this is what I wish to have
func DisplayAddress(){
city.text = city
postCode.text = postCode
}

Answer 1

I may be totally reading the question wrong but in trying to read into your question, I think the terminology may be where clarification is needed; Object vs Array
An object has properties - lets examine the Details() object
var msgObj = Details()
which contains address information for one user. So conceptually this is how it would be represented in FireStore
users
this_user
address
city: "some city"
country: "some country"
county: "some county"
line1: "line one"
the 'documents' are the items stored within the address collection
city: "some city"
country: "some country"
county: "some county"
line1: "line one"
and your Details() object has properties that correspond to those documents and stores them as properties within the object; city, county etc
msgObj.city = city
msgObj.country = country
On the other hand, an array contains a series of objects, not properties. e.g. an array would generally not contain city, country etc, but it would contain a series of Details() objects and each of those Detail() objects has it's properties of city, country etc. For example, suppose you want to work with addresses of several different users - you would create a Details() object for each user, which contains their address information and append each one to an array.
self.dataArry[0] = the Details() objects of one user
self.dataArry[1] = the Details() object of another user
self.dataArry[2] = the Details() object of a third user
You could then, for example, display the users within a certain radius of this user, or send them all an email etc.
To answer your question, if you are working with a single users address information there is no need for an array, you can simply store it as a single Details() object variable within the class.
class ViewController: UIViewController {
var myUserAddress = Details()
func to get this users address documents from FireStore {
if let city = msgdata["city"] as? String {
self.myUserAddress.city = city
}
if let country = msgdata["country"] as? String {
self.myUserAddress.country = country
}
//remember that the properties are only valid from here on
//as FireStore is asychronous
self.DisplayCity()
self.DisplayLocation()
}
//and then later on when you want to display those properties
func DisplayCity() {
let city = self.myUserAddress.city
print(city)
}
func DisplayLocation() {
let lon = self.myUserAddress.logitude
let lat = self.myUserAddress.latitude
//show the location on a map via lon & lat
}