How to change Swift version from 5 to 4 in Xcode?

问题

I am programming with Swift in Xcode (MacBook Air 2015) and I want to change my Swift version from 5 to 4. How to do that?

回答1:

Project ► (Select Your Project Target) ► Build Settings ► (Type
'swift_version' in the Search bar) Swift Compiler Language ► Swift
Language Version ► Click on Language list

Here you can change your version.

来源：https://stackoverflow.com/questions/56894082/how-to-change-swift-version-from-5-to-4-in-xcode