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Questions tagged [swift]

Swift is a general-purpose programming language developed by Apple Inc first released in 2014 for its platforms and Linux. Swift is open-source. Use the tag only for questions about language features or requiring code in Swift. Use the tags [ios], [ipados], [macos], [watch-os], [tvos], [swiftui], [cocoa-touch], and [cocoa] for (language-agnostic) questions about the platforms or frameworks.

Swift is an application and systems programming language introduced by Apple on June 2, 2014, and distributed as open source. Swift interoperates with Objective-C and Cocoa/Cocoa Touch APIs for Apple's iOS, macOS, watchOS, tvOS, and iPadOS operating systems.

Current stable version is Swift 5.8.0 released on November 1, 2022 (download).

  • Swift is open-source, available on GitHub
  • Swift >=2.2 includes support for Swift on a Linux platform.
  • Swift >=5.3 includes support for Swift on a Windows platform.

Please use the tag for questions relating to OpenStack's object/blob store, and the tag for questions relating to the parallel scripting language.

Swift promises to modernize the developer experience over what Objective-C provides, offering features like:

  • Generics
  • Type safety
  • Type inference
  • Namespaces
  • Improved safety (some protection from overflow, use-before-initialization, etc.)
  • Higher-order functions (map, filter, sort)

among others.

The Swift syntax retains some elements from Objective-C while providing an extensive new vocabulary for its new features.

The language can use existing iOS and macOS frameworks, like Cocoa and Cocoa Touch, and can sit side-by-side with Objective-C in applications. Swift applications compile into standard binaries and can be run on OS X 10.9, iOS 7 (or higher), tvOS and watchOS.

Timeline

  • Swift 2.0 was introduced by Apple at WWDC on 8th June 2015. They added new features like the "Error handling model" with try, throw and catch.

  • Swift 2.2 was introduced with Xcode 7.3 on 21st March 2016. (release notes)

  • Swift 3.0 was introduced by Apple at WWDC on 13th June 2016, with the news that Swift will come to non-Apple platforms (Windows, Linux, Android, Raspberry Pi, and so on). (release notes)

  • Swift 3.1 was introduced with Xcode 8.3 on 27th March 2017. (release notes)

  • Swift 4.0 was introduced by Apple at WWDC on 5th June 2017. (release notes)

  • Swift 4.1 was introduced with Xcode 9.3 on 29th March 2018. (release notes)

  • Swift 4.2 was introduced by Apple at WWDC on 4th June 2018. (release notes)

  • Swift 5.0 was introduced with Xcode 10.2 on 25th March 2019. (release notes)

  • Swift 5.1 was introduced with Xcode 11 on 20th September 2019. (release notes)

  • Swift 5.2 was introduced with Xcode 11.4 on 24th March 2020. (release notes)

  • Swift 5.3 was introduced with Xcode 12 on 16th September 2020. (release notes)

  • Swift 5.4 was introduced with Xcode 12.5 on 26th April 2021. (release notes)

  • Swift 5.5 was introduced with Xcode 13 on 20th September 2021. (release notes)

  • Swift 5.6 was introduced with Xcode 13.3 on 14th March 2022. (release notes)

  • Swift 5.7 was introduced with Xcode 14 on 12th September 2022. (release notes)

  • Swift 5.8 was introduced with Xcode 14.3 on 30th March 2023. (release notes)

Resources

References

Books

Other resources

Related Tags

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What does "Fatal error: Unexpectedly found nil while unwrapping an Optional value" mean?

My Swift program is crashing with EXC_BAD_INSTRUCTION and one of the following similar errors. What does this error mean, and how do I fix it? Fatal error: Unexpectedly found nil while unwrapping an Optional value or Fatal error: Unexpectedly…
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I've been updating some of my old code and answers with Swift 3 but when I got to Swift Strings and Indexing with substrings things got confusing. Specifically I was trying the following: let str = "Hello, playground" let prefixRange =…
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In Swift 2, I was able to use dispatch_after to delay an action using grand central dispatch: var dispatchTime: dispatch_time_t = dispatch_time(DISPATCH_TIME_NOW, Int64(0.1 * Double(NSEC_PER_SEC))) dispatch_after(dispatchTime,…
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Static vs class functions/variables in Swift classes?

The following code compiles in Swift 1.2: class myClass { static func myMethod1() { } class func myMethod2() { } static var myVar1 = "" } func doSomething() { myClass.myMethod1() myClass.myMethod2() myClass.myVar1 =…
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475
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How do I get a reference to the AppDelegate in Swift?

How do I get a reference to AppDelegate in Swift? Ultimately, I want to use the reference to access the managed object context.
AperioOculus
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I am trying to run a Swift app on my iPhone 4s. It works fine on the simulator, and my friend can successfully run it on his iPhone 4s. I have iOS 8 and the official release of Xcode 6. I have tried Restarting Xcode, iPhone, computer Cleaning &…
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I have an UIImageView called "theImageView", with UIImage in a single color (transparent background) just like the left black heart below. How can I change the tint color of this image programmatically in iOS 7 or above, as per the tint method used…
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456
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NSNotificationCenter addObserver in Swift

How do you add an observer in Swift to the default notification center? I'm trying to port this line of code that sends a notification when the battery level changes. [[NSNotificationCenter defaultCenter] addObserver:self…
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Precision String Format Specifier In Swift

Below is how I would have previously truncated a float to two decimal places NSLog(@" %.02f %.02f %.02f", r, g, b); I checked the docs and the eBook but haven't been able to figure it out. Thanks!
user3524868
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448
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21 answers

How to make HTTP request in Swift?

I read The Programming Language Swift by Apple in iBooks, but cannot figure out how to make an HTTP request (something like cURL) in Swift. Do I need to import Obj-C classes or do I just need to import default libraries? Or is it not possible to…
Dicky Tsang
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442
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25 answers

How do I convert a Swift Array to a String?

I know how to programmatically do it, but I'm sure there's a built-in way... Every language I've used has some sort of default textual representation for a collection of objects that it will spit out when you try to concatenate the Array with a…
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40 answers

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I am trying to use hex color values in Swift, instead of the few standard ones that UIColor allows you to use, but I have no idea how to do it. Example: how would I use #ffffff as a color?
Stephen Fox
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433
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9 answers

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I can see these definitions in the Swift library: extension Bool : BooleanLiteralConvertible { static func convertFromBooleanLiteral(value: Bool) -> Bool } protocol BooleanLiteralConvertible { typealias BooleanLiteralType class func…
Jean-Philippe Pellet
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Get class name of object as string in Swift

Getting the classname of an object as String using: object_getClassName(myViewController) returns something like this: _TtC5AppName22CalendarViewController I am looking for the pure version: "CalendarViewController". How do I get a cleaned up…
Bernd
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How does one declare optional methods in a Swift protocol?

Is it possible in Swift? If not then is there a workaround to do it?
Selvin
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