---
title: Objective-C and C Code Customization
framework: swift
role: collectionGroup
path: swift/objective-c-and-c-code-customization
---

# Objective-C and C Code Customization

Apply macros to your Objective-C APIs to customize how they’re imported into Swift.

## Topics

### Customizing Objective-C APIs

- [Designating Nullability in Objective-C APIs](swift/designating-nullability-in-objective-c-apis.md)
- [Renaming Objective-C APIs for Swift](swift/renaming-objective-c-apis-for-swift.md)
- [Improving Objective-C API Declarations for Swift](swift/improving-objective-c-api-declarations-for-swift.md)
- [Grouping Related Objective-C Constants](swift/grouping-related-objective-c-constants.md)
- [Marking API Availability in Objective-C](swift/marking-api-availability-in-objective-c.md)
- [Making Objective-C APIs Unavailable in Swift](swift/making-objective-c-apis-unavailable-in-swift.md)

### Customizing C APIs

- [Customizing Your C Code for Swift](swift/customizing-your-c-code-for-swift.md)

## See Also

### Language Interoperability with Objective-C and C

- [Migrating Your Objective-C Code to Swift](swift/migrating-your-objective-c-code-to-swift.md)
- [Cocoa Design Patterns](swift/cocoa-design-patterns.md)
- [Handling Dynamically Typed Methods and Objects in Swift](swift/handling-dynamically-typed-methods-and-objects-in-swift.md)
- [Using Objective-C Runtime Features in Swift](swift/using-objective-c-runtime-features-in-swift.md)
- [Imported C and Objective-C APIs](swift/imported-c-and-objective-c-apis.md)
- [Calling Objective-C APIs Asynchronously](swift/calling-objective-c-apis-asynchronously.md)