What is Swift?
Writing code is interactive and fun, the syntax is concise yet expressive, and apps run lightning-fast. Swift is ready for your next iOS and OS X project — or for addition into your current app — because Swift code works side-by-side with Objective-C.
What is SwiftUI?
Provides views, controls, and layout structures for declaring your app’s user interface. The framework provides event handlers for delivering taps, gestures, and other types of input to your app.
SwiftUI is an innovative, exceptionally simple way to build user interfaces across all Apple platforms with the power of Swift. With a declarative Swift syntax that’s easy to read and natural to write, SwiftUI works seamlessly with new Xcode design tools to keep your code and design perfectly in sync.
What are some alternatives to Swift and SwiftUI?
Objective-C
Objective-C is a superset of the C programming language and provides object-oriented capabilities and a dynamic runtime. Objective-C inherits the syntax, primitive types, and flow control statements of C and adds syntax for defining classes and methods. It also adds language-level support for object graph management and object literals while providing dynamic typing and binding, deferring many responsibilities until runtime.
React Native
React Native enables you to build world-class application experiences on native platforms using a consistent developer experience based on JavaScript and React. The focus of React Native is on developer efficiency across all the platforms you care about – learn once, write anywhere. Facebook uses React Native in multiple production apps and will continue investing in React Native.
Kotlin
Kotlin is a statically typed programming language for the JVM, Android and the browser, 100% interoperable with Java
Go
Go is expressive, concise, clean, and efficient. Its concurrency mechanisms make it easy to write programs that get the most out of multicore and networked machines, while its novel type system enables flexible and modular program construction. Go compiles quickly to machine code yet has the convenience of garbage collection and the power of run-time reflection. It’s a fast, statically typed, compiled language that feels like a dynamically typed, interpreted language.
Java
Java is a programming language and computing platform first released by Sun Microsystems in 1995. There are lots of applications and websites that will not work unless you have Java installed, and more are created every day. Java is fast, secure, and reliable. From laptops to datacenters, game consoles to scientific supercomputers, cell phones to the Internet, Java is everywhere!