How to write a closure that returns a value
Like regular functions, closures can accept values and return values of your choosing: just write them out at the start of your closure, followed by the word in.
For example, we could write a greeting closure that accepts the name of a person to greet and returns a string using that name:
let greeting = { (name: String) -> String in
return "Hello, \(name)!"
}You can now call that just like any other function, passing in someone’s name as its only parameter:
let message = greeting("Taylor")Sponsored You’re already busy updating your app for Swift 4.2 and iOS 12, so why not let Instabug help you find and fix bugs? Add just two lines of code to your project and receive comprehensive reports with all the feedback you need to ship a world-class app – click here to learn more!
Available from iOS 8.0
Did this solution work for you? Please pass it on!
Other people are reading…
- Tips for Android developers switching to Swift
- How to use the rethrows keyword
- How to fix the error “Expression was too complex to be solved in reasonable time”
- How to convert a string to a double
- What are lazy variables?
About the Swift Knowledge Base
This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.
Help support Hacking with Swift
This site is funded by Hacking with Swift supporters who buy my e-books. If you can, please support my work – it comes packed with bonus material!
