vialyx

for (index, user) in allUsers.enumerated() {
    print("User: \(user) at index: \(index)")
    /*
     User: User(id: 654, name: "Chilly Mango") at index: 0
     User: User(id: 7, name: "Mike Biggles") at index: 1
     User: User(id: 234, name: "Midum Premium") at index: 2
     User: User(id: 99, name: "Jimmy Cho") at index: 3
     */
}

vialyx

let premiumUsers: Set<User> = [User(id: 654, name: "Chilly Mango"),
                               User(id: 234, name: "Midum Premium"),
                               User(id: 7, name: "Mike Biggles"),
                               User(id: 99, name: "Jimmy Cho")]

let firstHundredUsers: Set<User> = [User(id: 99, name: "Jimmy Cho"),
                                    User(id: 7, name: "Mike Biggles")]

let intersection = premiumUsers.intersection(firstHundredUsers)
// {{id 99, name "Jimmy Cho"}, {id 7, name "Mike Biggles"}}

vialyx

var countedAdmins: NSCountedSet = NSCountedSet(array: [user])
countedAdmins.count(for: user)
// count is 1
countedAdmins.add(user)
countedAdmins.count(for: user)
// count is 2

vialyx

struct User {
    let name: String
}

var users: [Int: User] = []

vialyx

let user = User(name: "Medium Guest")
users[120] = user
print("users count: \(users.count)")
// users count: 1

users.removeValue(forKey: 100)
print("users count: \(users.count)")
// users count: 1

users.removeAll()

vialyx

var users: [String: User] = [:]
users["admin"] = user
users["guest"] = User(name: "Antonio Guest")

if users.isEmpty {
    print("User dictionary is empty")
} else {
    let user = users["admin"]
    print("Admin user is: \(String(describing: user))")
    // "Admin user is: Optional(__lldb_expr_59.User(name: "Medium Guest"))\n"

vialyx

var users: [String: User] = [:]
users["admin"] = user
users["guest"] = User(name: "Antonio Guest")

for item in users {
    print("item: \(item)")
    print("key: \(item.key)")
    print("value: \(item.value)")
    /*
     item: (key: "admin", value: __lldb_expr_67.User(name: "Medium Guest"))

vialyx

let premiumUser = users["premium", default: User(name: "Anonymous")]
print("premiumUser: \(premiumUser)")
// Default result - "premiumUser: User(name: "Anonymous")\n"

vialyx

users = ["123": User(name: "Max Guest"), "222": User(name: "Mark Towrn"), "333": User(name: "James Jo")]

let grouppedByFirstNameCharacter = Dictionary(grouping: users) {
    return $0.value.name.first!
}

print("groupped: \(grouppedByFirstNameCharacter)")
// groupped: ["J": [(key: "333", value: __lldb_expr_82.User(name: "James Jo"))], "M": [(key: "222", value: __lldb_expr_82.User(name: "Mark Towrn")), (key: "123", value: __lldb_expr_82.User(name: "Max Guest"))]]

vialyx

//: A UIKit based Playground for presenting user interface
  
import UIKit
import PlaygroundSupport

class HexagonView: UIView {
    
    private let borderLineWidth: CGFloat = 4
    var borderLineColor: UIColor = .clear