Skip to content
Learn Netverks

Lesson

Step 1/36 3% through track

intro

Introduction to Swift

Last reviewed May 28, 2026 Content v20260528
Track mode
server_compiled
Means
Compiled runner
Reading
~3 min
Level
beginner

This lesson

An orientation to the Swift track—how the compiled playground works, core vocabulary, and what you will practice next.

You need a clear map of the Swift track so optionals, value types, protocols, and ARC do not feel like magic.

You will apply Introduction to Swift in contexts like: iPhone/iPad/Mac apps, server-side Swift (niche), and Apple toolchain projects.

Write Swift in main.swift with print(), click Run on server—the dev runner swiftc compiles and runs the binary (requires Swift toolchain, typically macOS; LEARNING_RUNNER_ENABLED=true). Also read the interview prep blocks.

After JavaScript or Kotlin/Java OOP basics—Swift is approachable but optionals and value types need deliberate practice.

How this Swift track works

  • swiftc in the playground — write a single main.swift with top-level print() or an @main entry; the dev runner compiles with swiftc on macOS and runs the binary.
  • Language-first, Apple platforms as context — lessons teach Swift syntax, value types, optionals, and protocols. SwiftUI and UIKit appear as teasers—full iOS/macOS apps run locally in Xcode with the Apple SDK.
  • Prerequisites — finish general programming basics (variables, functions, types). Compare with Kotlin, JavaScript, Java, and C# when choosing stacks.

Swift powers iOS, iPadOS, macOS, watchOS, and tvOS apps. Xcode projects, Swift Package Manager, and SwiftUI run locally on Apple toolchains—sandbox lessons keep one file without UIKit/SwiftUI imports.

Install on your device (macOS, Linux, Windows)

Swift toolchain is native on macOS; Linux/Windows use swift.org builds for CLI practice (no iOS Simulator in this track).

macOS

  1. Install Xcode from the App Store (includes swiftc).
  2. CLI only: xcode-select --install then swift --version.

Linux

  1. Install per swift.org/install/linux (Ubuntu 22.04+ packages).

Windows

  1. Swift for Windows is experimental—see swift.org/install/windows. For iOS development use a Mac.

Verify: swift --version on macOS or Linux.

Run code on this site (Backend & language playgrounds)

  1. Clone or open this project locally; copy .env.example to .env.
  2. Ensure LEARNING_RUNNER_ENABLED=true and LEARNING_RUNNER_URL=http://127.0.0.1:9999/v1/execute.
  3. Terminal 1: php artisan serve (or composer run dev for Laravel + Vite + runner together).
  4. Terminal 2: npm run runner — keep it running while you click Run on server.

Note: iOS/SwiftUI apps require Xcode on macOS; playground lessons use command-line Swift only.

Swift is Apple’s modern, statically typed language for iOS, macOS, watchOS, and tvOS—and increasingly for server-side and cross-platform tooling. It combines value-type ergonomics, protocol-oriented design, and optional safety with a readable syntax that feels familiar if you know Kotlin, Java, or C#.

How this track differs from JavaScript and Kotlin

Unlike browser-first JavaScript, Swift targets compiled Apple platforms and CLI tools with swiftc in the playground. Compared to Kotlin on the JVM, Swift emphasizes structs, ARC memory management, and Apple SDK integration rather than JVM bytecode and coroutines on Android.

This track teaches Swift language fundamentals first—UIKit and SwiftUI appear as context; full app UI runs locally in Xcode with the Apple SDK.

What you will learn

  • Syntax: variables, types, strings, control flow, functions, and optionals
  • Collections: arrays, dictionaries, sets, tuples, enums, and pattern matching
  • OOP: structs, classes, properties, protocols, extensions, and generics
  • Modern Swift: errors, closures, property wrappers, concurrency, and ARC
  • Tooling: modules, SPM, file I/O, testing, Codable/JSON
  • Interview essentials, production habits, and SwiftUI context

Playground setup

This topic uses server_compiled: your code compiles with swiftc as a single main.swift file. Use top-level print() for output—avoid UIKit/SwiftUI imports in runnable snippets. Foundation is fine when needed.

Important interview questions and answers

  1. Q: What is Swift best known for?
    A: Safe optionals, value types (structs), protocol-oriented APIs, ARC memory management, and first-class Apple platform development.
  2. Q: Does Swift replace Objective-C?
    A: Swift is the preferred language for new Apple code; Objective-C remains for legacy frameworks and mixed codebases.

Self-check

  1. In one sentence, why do iOS teams prefer Swift?
  2. What filename does the playground expect?

Tip: Compare with Kotlin and JavaScript—Swift targets Apple platforms with value types and ARC.

Interview prep

What is Swift in one sentence?

A modern statically typed Apple language with optionals, value types, protocols, and ARC—default for iOS and macOS apps.

Why compare with Kotlin and JavaScript?

Kotlin targets Android/JVM; JavaScript targets browsers; Swift targets native Apple platforms with compiled performance.

Interview tip Lesson completion confidence

Can you explain this lesson in 30 seconds without reading notes?

Not saved yet.

Playground

Runs on the configured server runner (dev: npm run runner with LEARNING_RUNNER_ENABLED=true). Output appears below the editor.

Check yourself

Multiple choice — immediate feedback.

Discussion

Past discussion is visible to everyone. Only logged-in users can post comments and replies.

Starter discussion topics

  • Why Swift for Apple?
  • iOS vs macOS goal?

Sign up or log in to post comments and sync lesson progress across devices.

No discussion yet. Be the first to ask a question.

Jump