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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

329921 questions
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How do I check if a string contains another string in Swift?

In Objective-C the code to check for a substring in an NSString is: NSString *string = @"hello Swift"; NSRange textRange =[string rangeOfString:@"Swift"]; if(textRange.location != NSNotFound) { NSLog(@"exists"); } But how do I do this in…
Rajneesh071
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UITextField text change event

How can I detect any text changes in a textField? The delegate method shouldChangeCharactersInRange works for something, but it did not fulfill my need exactly. Since until it returns YES, the textField texts are not available to other observer…
karim
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Do Swift-based applications work on OS X 10.9/iOS 7 and lower?

Will Swift-based applications work on OS X 10.9 (Mavericks)/iOS 7 and lower? For example, I have a machine running OS X 10.8 (Mountain Lion), and I am wondering if an application I write in Swift will run on it. Or what should I have to create a…
MeIr
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619
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34 answers

UIScrollView Scrollable Content Size Ambiguity

Fellow devs, I am having trouble with AutoLayout in Interface Builder (Xcode 5 / iOS 7). It's very basic and important so I think everyone should know how this properly works. If this is a bug in Xcode, it is a critical one! So, whenever I have a…
Wirsing
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How to enumerate an enum with String type?

enum Suit: String { case spades = "♠" case hearts = "♥" case diamonds = "♦" case clubs = "♣" } For example, how can I do something like: for suit in Suit { // do something with suit print(suit.rawValue) } Resulting…
Lucien
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8 answers

How can I make a weak protocol reference in 'pure' Swift (without @objc)

weak references don't seem to work in Swift unless a protocol is declared as @objc, which I don't want in a pure Swift app. This code gives a compile error (weak cannot be applied to non-class type MyClassDelegate): class MyClass { weak var…
hnh
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30 answers

Using a dispatch_once singleton model in Swift

I'm trying to work out an appropriate singleton model for usage in Swift. So far, I've been able to get a non-thread safe model working as: class var sharedInstance: TPScopeManager { get { struct Static { static var instance:…
David Berry
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Why are emoji characters like ‍‍‍ treated so strangely in Swift strings?

The character ‍‍‍ (family with two women, one girl, and one boy) is encoded as such: U+1F469 WOMAN, ‍U+200D ZWJ, U+1F469 WOMAN, U+200D ZWJ, U+1F467 GIRL, U+200D ZWJ, U+1F466 BOY So it's very interestingly-encoded; the perfect target for a unit test.…
Ky -
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dispatch_after - GCD in Swift?

I've gone through the iBook from Apple, and couldn't find any definition of it: Can someone explain the structure of dispatch_after? dispatch_after(<#when: dispatch_time_t#>, <#queue: dispatch_queue_t?#>, <#block: dispatch_block_t?#>)
Kumar KL
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24 answers

Any way to replace characters on Swift String?

I am looking for a way to replace characters in a Swift String. Example: "This is my string" I would like to replace " " with "+" to get "This+is+my+string". How can I achieve this?
user3332801
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How to add constraints programmatically using Swift

I'm trying to figure this out since last week without going any step further. Ok, so I need to apply some constraints programmatically in Swift to a UIView using this code: var new_view:UIView! = UIView(frame: CGRectMake(0, 0, 100,…
Sara Canducci
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564
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18 answers

How to check if an element is in an array

In Swift, how can I check if an element exists in an array? Xcode does not have any suggestions for contain, include, or has, and a quick search through the book turned up nothing. Any idea how to check for this? I know that there is a method find…
jaredsmith
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Swift: print() vs println() vs NSLog()

What's the difference between print, NSLog and println and when should I use each? For example, in Python if I wanted to print a dictionary, I'd just print myDict, but now I have 2 other options. How and when should I use each?
User
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17 answers

Why Choose Struct Over Class?

Playing around with Swift, coming from a Java background, why would you want to choose a Struct instead of a Class? Seems like they are the same thing, with a Struct offering less functionality. Why choose it then?
bluedevil2k
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How would I create a UIAlertView in Swift?

I have been working to create a UIAlertView in Swift, but for some reason I can't get the statement right because I'm getting this error: Could not find an overload for 'init' that accepts the supplied arguments Here is how I have it…
BlueBear
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