Async/Await in Swift: Modern Concurrency Patterns
Article Summary
Asukhija from Expedia Group shows how two simple keywords can eliminate callback hell in Swift. If you've ever drowned in nested closures, this is your lifeline.
Apple introduced async/await in Swift during WWDC 2021, bringing JavaScript-style asynchronous programming to iOS. This article walks through a real-world travel app example, showing how to refactor nested API calls for trip cancellations and refund status checks into clean, readable code.
Key Takeaways
- Async/await eliminates nested closure pyramids with linear, readable code
- Mark functions with 'async' keyword, pause execution with 'await'
- Parallel execution possible by adding 'async let' before variables
- Real example: fetching trips and refund status becomes 70% less code
Swift's async/await transforms messy nested closures into clean, sequential code that's easier to write, read, and maintain.
About This Article
Expedia's iOS developers ran into callback hell when they chained multiple API calls together, like fetching user trips and then checking refund status. The deeply nested closures became hard to maintain and understand.
Asukhija used Swift's async/await keywords from WWDC 2021 to replace completion handlers with straightforward, sequential code. The await keyword pauses execution until each asynchronous operation finishes.
The refactored code cut down complexity by getting rid of nested closure pyramids. The multi-step API workflow became much easier to read and maintain for Expedia's team.