Swift Key Path Expressions Example

KeyPathExampleViewController.swift

//
//  KeyPathExampleViewController.swift
//  UpgradeMySelf-ios
//
//  Created by Shubham Sharma on 09/05/22.
//  Copyright © 2022 Shubham Sharma. All rights reserved.
//

import UIKit


struct Car {
    var name: String
    var kind: String
}


class KeyPathExampleViewController: UIViewController {
 
   
    override func viewDidLoad() {
        super.viewDidLoad()
        
        tabBarItem.tag = TabbarItemTag.firstViewController.rawValue
        
        self.view.backgroundColor = .white
        
        
        
        print("Key paths Example-----")
        
        let keyPath = \Car.name // Create key path
        
        var audi = Car(name: "Audi", kind: "luxury") // Create instance of class or struct
        
        print(audi[keyPath: keyPath]) // Access the value of instance
        audi[keyPath: keyPath] = "Audi A8 L" // Update the value of instance
        print(audi[keyPath: keyPath])
        
        print(audi[keyPath: \.kind]) // Short hand version of key path
        
        let cars = [
            audi,
            Car(name: "Škoda", kind: "comfort")
        ]
        
        let carNameList = cars.map(\.name) // in Swift 5.2 we can pass key path as function
        
        print(carNameList)
        
        print("End of Key paths Example-----")
        
    } 
}