Once you’ve made the decision to move to a Swift code base, you don’t have to do it all at once. In fact, it’s perfectly fine to leave some parts of your app in Objective-C.

Think of the migration as a marathon, not a sprint. You want to make sure you do it right. You want to make sure that you finish it with a healthy code base.

Small, Focused Changes

As with most challenges in software development, it’s much easier to take it one step at a time. Converting an entire code base at once can leave a lot on your hands to deal with. Rather do your conversion in small, focused increments. Make a change, test that the project still works, and then repeat.

What Should I Leave in Objective-C?

Third-party Libraries

You won’t be able to convert your third-party Objective-C libraries to Swift, and there’s nothing wrong with that. Xcode offers great interoperability between Objective-C and Swift.

Read more.