Swift

export PATH=/Library/Developer/Toolchains/swift-latest.xctoolchain/usr/bin:"${PATH}"

Hello World

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var nameTexField: UITextField!
    @IBOutlet weak var ageTextField: UITextField!
    @IBOutlet weak var helloLabel: UILabel!
    

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func clickMeAction(_ sender: Any) {
        print("Hello \(nameTexField.text!)");
        helloLabel.text = "Hello \(nameTexField.text!), your age is \(ageTextField.text!)";
    }
}

Alert & Action

import UIKit

class ViewController: UIViewController {
    
    @IBOutlet weak var nameTexField: UITextField!
    @IBOutlet weak var ageTextField: UITextField!
    @IBOutlet weak var helloLabel: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()
    }

    @IBAction func clickMeAction(_ sender: Any) {
        print("Hello \(nameTexField.text!)")
        helloLabel.text = "Hello \(nameTexField.text!), your age is \(ageTextField.text!)"
    }
    
    @IBAction func showAlertAction(_ sender: UIButton) {
        let alertCtrl = UIAlertController(title: "Alert", message: "Hello Alert", preferredStyle: .alert)
        let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
        alertCtrl.addAction(okAction)
        present(alertCtrl, animated: true, completion: nil)
    }
    
    @IBAction func showConfirmAction(_ sender: UIButton) {
        let actionSheet = UIAlertController(title: "Hello World", message: "This is an Action Sheet", preferredStyle: .actionSheet)
        let okAction = UIAlertAction(title: "OK", style: .default, handler: nil)
        actionSheet.addAction(okAction)
        present(actionSheet, animated: true, completion: nil)
    }
}

Features

1. Closures unified with function pointers
2. Tuples and multiple return values
3. Generics
4. Fast and concise iteration over a range or collection
5. Structs that support methods, extensions, and protocols
6. Functional programming patterns, e.g., map and filter
7. Powerful error handling built-in
8. Advanced control flow with do, guard, defer, and repeat keywords

References

• Swift LLVM, Swift Docker
• Swift, Swift Clang
• iOS Chat Tutorial
• Swift Community
• Download Swift
• About Swift