Introduction to Swift

## Learning Objectives - Understand Swift history and evolution - Set up Swift development environment - Write and run your first Swift program - Understand Swift syntax basics ## What is Swift? Swift is a powerful, intuitive programming language developed by Apple for building apps for iOS, Mac, Apple TV, and Apple Watch. It was designed to be easy to learn and use while being expressive and modern. ```swift print("Hello, World!") ``` ## Swift History | Year | Version | Milestone | |------|---------|-----------| | 2014 | Swift 1.0 | Initial release | | 2015 | Swift 2.0 | Open source, protocol extensions | | 2016 | Swift 3.0 | API design guidelines, Linux support | | 2017 | Swift 4.0 | Improved generics, string handling | | 2019 | Swift 5.0 | ABI stability, SwiftUI announced | | 2023 | Swift 5.9 | Macro support, if/switch expressions | ## Key Features - **Safe**: Built-in memory safety and type safety - **Fast**: Performance-optimized compiled language - **Modern**: Concise syntax, optionals, closures - **Interactive**: Playgrounds for experimentation - **Open Source**: Available on GitHub ## Installing Swift ### macOS Swift comes pre-installed with Xcode. To verify: ```bash swift --version ``` ### Linux Download from : ```bash # Ubuntu (example) wget https://download.swift.org/swift-5.9.2-release/ubuntu2204/swift-5.9.2-RELEASE-swift-5.9.2-RELEASE-ubuntu22.4.tar.gz tar xzf swift-5.9.2-RELEASE-* export PATH=/path/to/swift-5.9.2-RELEASE-ubuntu22.4/usr/bin:"$PATH" ``` ### Verify Installation ```bash swift --version # Swift version 5.9.2 ``` ## Your First Program ### Hello World ```swift print("Hello, World!") ``` ### Using Variables ```swift let name = "Swift" let version = 5.9 print("Welcome to \(name) \(version)") ``` ## Swift Playgrounds Playgrounds provide an interactive environment to write and test Swift code. ### Creating a Playground (Xcode) 1. Open Xcode 2. File > New > Playground 3. Select iOS or macOS 4. Name your playground 5. Start coding! ### Playground Benefits - Instant feedback - Experiment freely - Visualize data - Test algorithms ## Swift Program Structure ### Basic Structure ```swift // Entry point import Foundation let message = "Hello" print(message) ``` ### Multiple Statements ```swift let a = 10 let b = 20 let sum = a + b print("Sum: \(sum)") ``` ## Comments ```swift // Single-line comment /* Multi-line comment */ /** Documentation comment (used by Xcode) */ ``` ## Data Types Preview ```swift // Integers let age: Int = 25 // Floating-point let price: Double = 19.99 // Strings let name: String = "Swift" // Booleans let isActive: Bool = true // Arrays let numbers: [Int] = [1, 2, 3] // Dictionaries let person: [String: Any] = ["name": "Alice", "age": 30] ``` ## Command Line ### Running Swift Files ```bash swift MyFile.swift ``` ### Compiling ```bash swiftc -o MyProgram MyFile.swift ./MyProgram ``` ## IDEs ### Xcode (Recommended) - Native Apple IDE - Built-in playgrounds - Interface Builder - Debugger ### VS Code - Install Swift extension - Syntax highlighting - IntelliSense ### Swift Playgrounds App - iPad app - Interactive coding - Great for learning ## Swift vs Other Languages | Feature | Swift | Objective-C | Java | |---------|-------|-------------|------| | Type Safety | Strong | Weak | Strong | | Memory Safety | Yes | Manual | Yes | | Syntax | Modern | C-based | C-based | | Optionals | Built-in | Nil objects | No | | Closures | Native | Blocks | Lambdas | ## Summary - Swift is Apple's modern programming language - Available on macOS, Linux, and Windows - Swift Playgrounds enable interactive learning - Type-safe and memory-safe by default - Run with `swift filename.swift` - Comments: `//`, `/* */`, `/** */`