I’m sorry but they were all built to be compatible with Xcode 10. There’s nothing inherently “version 10” specific about the push notification tutorials though. Note that you can have multiple version of Xcode installed at once and switch between them. Google “multiple xcode versions” and you’ll see lots of articles showing you how to do it.
In essence though you just rename /Applications/Xcode.app to /Applications/Xcode9.app, then install Xcode 10 from the app store like normal.
You can then use the xcode-select command to switch between them via either of these commands depending on the version you want:
- sudo xcode-select -s /Applications/Xcode.app/Contents/Developer
- sudo xcode-select -s /Applications/Xcode9.app/Contents/Developer
And then run the appropriate one. You can’t have both versions running at the same time though. It gets very unhappy if you do that.