Swift

Lessons

1. 1Hello, SwiftWrite and run your first Swift program and learn let, var and Swift's basic types. Swift has concise syntax with no semicolons, and it compiles to fast native code.
2. 2OptionalsLearn optionals, Swift's way of handling values that might be missing. A String? is a different type from a String, and the compiler makes you handle the missing case before you use it.
3. 3Functions & Control FlowLearn how to write functions with argument labels, and how to branch with if and switch. Swift's switch can match ranges and patterns, so it often replaces long if-else chains.
4. 4Structs, Enums & Value TypesLearn structs, enums and the difference between value and reference types. In Swift, structs are copied on assignment and are the usual choice, and enum cases can carry data.
5. 5Collections & ClosuresLearn arrays, dictionaries and sets, and how to transform them with closures and map, filter and reduce, including the short $0 syntax.
6. 6Errors & async/awaitLearn how to throw and handle errors and how to call asynchronous code with async/await. Swift marks both in the code: throws in a function signature and await at the call site.
7. 7Your First SwiftUI AppBuild a simple counter app with SwiftUI. You describe screens as structs, and SwiftUI updates them when @State values change.
8. 8Swift CheatsheetOptionals, structs, enums, closures, and SwiftUI basics on one page.

Install it on your own computer

Building iOS apps requires Xcode, which only runs on a Mac. The language itself also runs on Linux and Windows, and the Swift Playgrounds app on iPad or Mac is a good way to learn.

# Swift toolchain for Windows exists (swift.org/install),
# but you cannot build iOS apps on Windows.
winget install Swift.Toolchain

swift --version
swift run          # in a package folder

# Realistic options for iOS without a Mac:
# - Swift Playgrounds on an iPad
# - online: swiftfiddle.com

What people build with Swift

Learn the basics first, then pick up these tools when a project needs them.