Welcome to Swift

Swift is a new object-oriented programming language for iOS and OS X development. Swift is modern, powerful, and easy to use.

  • let people = ["Anna": 67, "Beto": 8, "Jack": 33, "Sam": 25]
  • for (name, age) in people {
  • println("(name) is (age) years old.")
  • }

 

Safe

Swift pairs increased type safety with type inference, restricts direct access to pointers, and automatically manages memory—making it easy to create secure, stable software.

  • func configureLabels(labels: [UILabel]) {
  • let labelTextColor = UIColor.greenColor()
  • for label in labels {
  • // label inferred to be UILabel
  • label.textColor = labelTextColor
  • }
  • }

Modern

Swift includes optionals, generics, tuples, and other modern language features. Inspired by and improving upon Objective-C, Swift code feels natural to read and write.

  • let cities = ["London", "San Francisco", "Tokyo", "Barcelona", "Sydney"]
  • let sortedCities = sorted(cities) { $0 < $1 }
  • if let indexOfLondon = find(sortedCities, "London") {
  • println("London is city number (indexOfLondon + 1) in the list")
  • }

Powerful

Take advantage of powerful pattern matching in Swift to write simple, expressive code. Format strings naturally with string interpolation. Use frameworks like Foundation and UIKit directly from Swift.

  • let size = (20, 40)
  • switch size {
  • case let (width, height) where width == height:
  • println("square with sides (width)")
  • case (1...10, 1...10):
  • println("small rectangle")
  • case let (width, height):
  • println("rectangle with width (width) and height (height)")
  • }

Interactive

Use playgrounds to experiment with new technologies, analyze problems, and prototype user interfaces.

Fast

The Swift compiler applies advanced code analysis to tune your code for performance, letting you focus on writing great apps instead of on implementing complex optimizations.

The Swift Programming Language

The complete guide and reference to the Swift programming language.

  • A Swift Tour

    Take an interactive tour of language features that make app development easier, faster, and more reliable.

  • Language Guide

    Learn Swift concepts, principles, and syntax through comprehensive descriptions and code examples.

  • Language Reference

    Dive into the details of the language with a thorough discussion of its behavior, syntax, and grammar.

Using Swift with Cocoa and Objective-C

Tools and strategies for integrating Swift into the Cocoa app development process.

  • Getting Started

    Learn how to interact with Cocoa frameworks in a Swift environment.

  • Interoperability

    Take advantage of Swift language features to build on Objective-C APIs, and improve the way you write Cocoa apps.

  • Mix and Match

    Create a mixed-language app using Swift and Objective-C.

  • Migration

    Explore strategies to migrate your app to Swift.