Assign keys and values from [(key: String, value: [[String : Any]])] in UITableView - ios

Question

I have an array of dictionaries, [[String:AnyObject]], which is reduce+sorted as below successfully.
var arrUserList = [(key: String, value: [[String : Any]])]()
let result = self.arrJsonDict.reduce(into: [String: [[String:Any]]]()) { result, element in
let strName: String = (element as! NSDictionary).value(forKey: "name") as! String
if let firstLetter = strName.first {
let initial = String(describing: firstLetter).uppercased()
result[initial, default: [[String:Any]]() ].append(element as! [String : Any])
}}.sorted { return $0.key < $1.key }
self.arrUserList = result
Now I wanted to assign keys to table sections and values as table cell text from the array.

Answer 1

This is very cumbersome code.
You are highly encouraged to use a struct rather than a dictionary at least with a member name
struct Person {
let name : String
}
Declare and rename arrJsonDic (more descriptively) as
var people : [Person]()
and arrUserList as
var users = [String: [Person]]()
For the sections declare another array
var letters = [String]()
Group the array and populate letters simply with
users = Dictionary(grouping: people, by: { String($0.name.first!) })
letters = users.keys.sorted()
In the table view in numberOfSections return
return letters.count
and in numberOfRows return
let letter = letters[section]
return users[letter]!.count
In cellForRowAt assign a name to a label with
let letter = letters[indexPath.section]
let user = users[letter]![indexPath.row]
cell.nameLabel.text = user.name
------------------------------
To make it still swiftier declare a second struct Section
struct Section {
let index : String
let people : [Person]
}
delete
var letters = [String]()
and declare users
var users = [Section]()
The grouping is slightly different
let grouped = Dictionary(grouping: people, by: { String($0.name.first!) })
users = grouped.map({ Section(index: $0.0, people: $0.1) }).sorted{$0.index < $1.index}
The code in the three table view delegate methods are
return users.count
-
return users[section].people.count
-
let user = users[indexPath.section].people[indexPath.row]
cell.nameLabel.text = user.name