Foundation

import Foundation

// Arrays
var numbers = [1, 2, 3, 4, 5]
numbers.append(6)
let doubled = numbers.map { $0 * 2 }

// Dictionaries
var userInfo: [String: Any] = [
    "name": "John Doe",
    "age": 30,
    "email": "john@example.com"
]

if let name = userInfo["name"] as? String {
    print("User: \(name)")
}

import Foundation

struct User: Codable {
    let id: Int
    let name: String
    let email: String
}

// Encoding
let user = User(id: 1, name: "John", email: "john@example.com")
let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted

if let jsonData = try? encoder.encode(user),
   let jsonString = String(data: jsonData, encoding: .utf8) {
    print(jsonString)
}

// Decoding
let jsonString = """
{"id": 1, "name": "John", "email": "john@example.com"}
"""
if let jsonData = jsonString.data(using: .utf8),
   let decoded = try? JSONDecoder().decode(User.self, from: jsonData) {
    print(decoded.name)
}

import Foundation

// Current date
let now = Date()

// Date formatting
let formatter = DateFormatter()
formatter.dateStyle = .medium
formatter.timeStyle = .short
let dateString = formatter.string(from: now)
print(dateString) // "Dec 3, 2025 at 2:30 PM"

// Date arithmetic
let calendar = Calendar.current
if let tomorrow = calendar.date(byAdding: .day, value: 1, to: now) {
    print("Tomorrow: \(tomorrow)")
}

// Date comparison
let futureDate = Date().addingTimeInterval(3600)
if futureDate > now {
    print("futureDate is later")
}