Swift
Swift is a general-purpose, multi-paradigm programming language developed by Apple for iOS, macOS, watchOS, tvOS, and server-side development. It is designed to be safe, fast, and expressive, with modern features like type inference, optionals, and memory management through Automatic Reference Counting (ARC). Swift interoperates seamlessly with Objective-C and is the primary language for Apple ecosystem development.
Developers should learn Swift when building applications for Apple platforms (iOS, macOS, etc.), as it is the recommended and most widely used language for this ecosystem, offering better performance and safety than Objective-C. It is also useful for server-side development with frameworks like Vapor, and its growing adoption makes it valuable for mobile and cross-platform roles targeting Apple devices.