SALE: Save 50% on all my books and bundles >>

How to check the Swift version at compile time

Swift version: 5.1

Paul Hudson    @twostraws   

Swift gives us the #if swift build configuration option, which lets you compile certain code only if a specific version of the Swift compiler is detected. This is particularly useful for libraries that need to support multiple incompatible versions of Swift at the same time, because only one version of their code will ever be compiled.

In the example below, the print() code will display one of two messages depending on whether you're using an old version of Swift:

#if swift(>=5.0)
print("Running Swift 5.0 or later")
#else
print("Running old Swift")
#endif
Hacking with Swift is sponsored by RevenueCat

SPONSORED Building in-app subscriptions are hard. RevenueCat makes it simple. With their open source SDKs, you can painlessly implement subscriptions for your app in hours, not months.

Explore the docs to learn more

Sponsor Hacking with Swift and reach the world's largest Swift community!

Snapthread is a casual video editor and slideshow maker that makes discovering, compiling and sharing your favorite memories effortless.

Available from iOS 7.0

Similar solutions…

About the Swift Knowledge Base

This is part of the Swift Knowledge Base, a free, searchable collection of solutions for common iOS questions.

BUY OUR BOOKS
Buy Pro Swift Buy Swift Design Patterns Buy Testing Swift Buy Hacking with iOS Buy Swift Coding Challenges Buy Swift on Sundays Volume One Buy Server-Side Swift (Vapor Edition) Buy Advanced iOS Volume One Buy Advanced iOS Volume Two Buy Advanced iOS Volume Three Buy Hacking with watchOS Buy Hacking with tvOS Buy Hacking with macOS Buy Dive Into SpriteKit Buy Swift in Sixty Seconds Buy Objective-C for Swift Developers Buy Server-Side Swift (Kitura Edition) Buy Beyond Code

Was this page useful? Let us know!