Optionals and Closures - Swift Typing CST Test

Optionals and Closures — Swift Code

Demonstrates Swift's type safety, optionals, and closure syntax with a practical example.

import Foundation

struct Person {
	let name: String
	let age: Int
	var email: String?
}

class PersonManager {
	private var people: [Person] = []
	
	func addPerson(_ person: Person) {
		people.append(person)
	}
	
	func findPeople(matching predicate: (Person) -> Bool) -> [Person] {
		return people.filter(predicate)
	}
	
	func updateEmail(for name: String, newEmail: String) -> Bool {
		if let index = people.firstIndex(where: { $0.name == name }) {
		people[index].email = newEmail
		return true
		}
		return false
	}
}

// Usage example
let manager = PersonManager()

let people = [
	Person(name: "Alice", age: 25, email: "alice@example.com"),
	Person(name: "Bob", age: 30, email: nil),
	Person(name: "Charlie", age: 35, email: "charlie@example.com")
]

people.forEach { manager.addPerson($0) }

let adults = manager.findPeople { $0.age >= 30 }
print("Adults: \(adults.map { $0.name })")

// Optional binding
for person in adults {
	if let email = person.email {
		print("\(person.name): \(email)")
	} else {
		print("\(person.name): No email")
	}
}

Swift Language Guide

Swift is a powerful, general-purpose, compiled programming language developed by Apple for iOS, macOS, watchOS, tvOS, and Linux. It emphasizes safety, performance, and modern programming practices.

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