vhart

struct Car: Drivable {
    let numberOfWheels = 4

    func drive() { }
}

struct Motorcycle: Drivable {
    let numberOfWheels = 2
    let licensePlate = "asdf123"

vhart

protocol Drivable {
    func drive()
    var numberOfWheels: Int { get }
}

func startTraveling(with transportation: Drivable) { }

func startTraveling<D: Drivable>(with transportation: D) { }

vhart

extension UIColor {
    convenience init? (fromHex hex: String) {
        let hexPattern = try! NSRegularExpression(pattern: "^[0-9a-fA-F]{6}$",
                                                  options: [.anchorsMatchLines])
        let range =  NSRange(location: 0, length: hex.characters.count)
        
        guard hexPattern.matches(in: hex, 
                                 options: [],
                                 range: range).count == 1 
        else { return nil }

vhart

//
//  main.m
//  variable2
//
//  Created by Varindra Hart on 6/4/15.
//  Copyright (c) 2015 Varindra Hart. All rights reserved.
//

#import <Foundation/Foundation.h>

vhart

//
//  main.m
//  12DaysOfChristmas
//
//  Created by Varindra Hart on 6/4/15.
//  Copyright (c) 2015 Varindra Hart. All rights reserved.
//

#import <Foundation/Foundation.h>