Objective-C

Objective-C is in maintenance mode. New features are rare, but it powers the Apple ecosystem's foundation. It allows mixing C++ (.mm) loosely.

When to Use

• Legacy iOS/macOS: Maintaining apps created before 2014.
• C++ Interop: Obj-C++ is often the bridge between C++ engines and Swift.
• Runtime Swizzling: Dynamic method replacement (used by Analytics SDKs).

Core Concepts

Message Passing

[object method:argument]. Dynamic binding at runtime.

ARC

Automatic Reference Counting. (Retain/Release).

Headers

.h (interface) and .m (implementation).

Best Practices (2025)

Do:

• Use Nullability Annotations: nullable, nonnull to aid Swift interop.
• Use Modern Syntax: @[@"a", @"b"] for arrays.
• Migrate to Swift: New features should be written in Swift.

Don't:

• Don't use manual retain/release: Always ensure ARC is on.

References

• Apple Developer Documentation