Swift Use Cases with Example Source Code

Swift is a powerful programming language used to develop software for iOS, macOS, and other Apple platforms. Here are some common use cases for Swift, along with examples of source code to help you get started:

1. iOS app development: Swift is the primary programming language used to develop iOS apps. Here’s an example of Swift code that creates a simple “Hello, World!” app:

   import UIKit
   
   class ViewController: UIViewController {
       override func viewDidLoad() {
           super.viewDidLoad()
           let label = UILabel(frame: CGRect(x: 0, y: 0, width: 200, height: 21))
           label.center = CGPoint(x: 160, y: 284)
           label.textAlignment = .center
           label.text = "Hello, World!"
           view.addSubview(label)
       }
   }
   

2. macOS app development: Swift can also be used to create macOS desktop applications. Here’s an example of Swift code that creates a simple window with a label:

   import Cocoa
   
   class ViewController: NSViewController {
       override func viewDidLoad() {
           super.viewDidLoad()
           let label = NSTextField(labelWithString: "Hello, World!")
           label.frame = NSRect(x: 20, y: 20, width: 200, height: 21)
           view.addSubview(label)
       }
   }
   

3. Server-side development: Swift can be used to create web applications and APIs using frameworks like Vapor and Kitura. Here’s an example of Swift code that creates a simple web server using the Vapor framework:

   import Vapor
   
   let app = Application()
   
   app.get("hello") { req -> String in
       return "Hello, World!"
   }
   
   app.run()
   

4. Machine learning: Swift can also be used for machine learning tasks using libraries like TensorFlow and Core ML. Here’s an example of Swift code that creates a simple neural network using TensorFlow:

   import TensorFlow
   
   let inputSize = 4
   let hiddenSize = 10
   let outputSize = 3
   
   var model = Sequential {
       Dense<Float>(inputSize: inputSize, outputSize: hiddenSize, activation: relu)
       Dense<Float>(inputSize: hiddenSize, outputSize: outputSize, activation: softmax)
   }
   
   let optimizer = SGD(for: model, learningRate: 0.01)
   
   // Train the model using a dataset of input/output pairs
   for (x, y) in dataset {
       let (loss, gradients) = valueWithGradient(at: model) { model -> Tensor<Float> in
           let logits = model(x)
           return softmaxCrossEntropy(logits: logits, labels: y)
       }
       optimizer.update(&model, along: gradients)
   }
   

These are just a few examples of the many use cases for Swift. With its simple syntax and powerful features, Swift is a versatile language that can be used for a wide range of programming tasks.