
This guide walks through how to build native iOS components for React Native using the older architecture. It explains when and why you might need to write native code, like when you need access to iOS-specific features, better performance, or existing native libraries. It also breaks down the differences between the old bridge-based approach and the newer JSI-based setup. Along the way, you’ll learn how to create native modules and UI components step by step, with clear examples in Objective-C and Swift. Important basics like common React Native macros and ways for JavaScript and native code to talk to each other—using callbacks, promises, and events—are covered in a straightforward way.


