iOS Topic wise code

Title	Description	Explanation	Link
Application Security.	Application Security Musts for every iOS App.	1. Don’t store sensitive in UserDefaults. By using a third party mac application like iMazing for the example, without even having to Jailbreak your device, you can easily view UserDefaults data for any app downloaded from the AppStore Keychain services API helps you solve these problems.	https://medium.com/swift2go/application-security-musts-for-every-ios-app-dabf095b9c4f
Create UILabel view outside viewDidLoad class	Create UILabel view outside viewDidLoad class and then add that view to your main view in viewDidLoad method.	1) Create UILabel view outside viewDidLoadclass and then add that view to your main view in viewDidLoad method. lazy var myLabel: UILabel = {     let label = UILabel(frame: CGRect(x: 10, y: 50, width: 230, height: 21))     label.translatesAutoresizingMaskIntoConstraints = false     label.text = "This is label view."     label.font = UIFont.systemFont(ofSize: 12)     return label }() 2) And then add that view in viewDidLoad() override func viewDidLoad() {     super.viewDidLoad()     view.addSubview(myLabel) }	https://stackoverflow.com/questions/24081731/how-to-create-uilabel-programmatically-using-swift/50654210#50654210
Variables creation	Let text: String var response: String? var temperature = 32.0 var width = 0.0, height = 0.0 let red, green, blue: Double
Call a function after some time		Option 1. =======     DispatchQueue.main.asyncAfter(deadline: .now() + 5.0) {         self.yourFuncHere()     }     //Your function here         func yourFuncHere() {          } Option 2. =======     perform(#selector(yourFuncHere2), with: nil, afterDelay: 5.0)              //Your function here       @objc func yourFuncHere2() {         print("this is...")     }          Option 3. =======     Timer.scheduledTimer(timeInterval: 5.0, target: self, selector: #selector(yourFuncHere3), userInfo: nil, repeats: false)     //Your function here       @objc func yourFuncHere3() {              } Option 4. =======     sleep(5) Option 5. ======= usleep(1000000)// will sleep for 1 sec usleep(2000)//Will slepp 0.002 milliseconds	https://stackoverflow.com/questions/27517632/how-to-create-a-delay-in-swift/54644329#54644329
Open URL		if UIApplication.shared.canOpenURL(url) {     //            UIApplication.shared.open(url, options: [:], completionHandler: nil)     //If you want handle the completion block than     UIApplication.shared.open(url, options: [:], completionHandler: { (success) in              print("Open url : \(success)")                           }) }
init()  {    }		//Initializers     //Init example 1     struct Fahrenheit {         var temperature: Double         init() {             temperature = 32.0         }     }          //Default Property Values     //Init example 2     struct Fahrenheit2 {         var temperature = 32.0     }          //Initialization Parameters     //Init example 3     struct Celsius {         var temperatureInCelsius: Double                  init(fromFahrenheit fahrenheit: Double) {             temperatureInCelsius = (fahrenheit - 32.0) / 1.8         }         init(fromKelvin kelvin: Double) {             temperatureInCelsius = kelvin - 273.15         }     }          //Parameter Names and Argument Labels     //Init example 4     struct Color {         let red, green, blue: Double         init(red: Double, green: Double, blue: Double) {             self.red   = red             self.green = green             self.blue  = blue         }         init(white: Double) {             red   = white             green = white             blue  = white         }     }          //Initializer Parameters Without Argument Labels     //Init example 5     struct Celsius2 {         var temperatureInCelsius: Double         init(fromFahrenheit fahrenheit: Double) {             temperatureInCelsius = (fahrenheit - 32.0) / 1.8         }         init(fromKelvin kelvin: Double) {             temperatureInCelsius = kelvin - 273.15         }         init(_ celsius: Double) {             temperatureInCelsius = celsius         }     }          //Initializer with init and function     //Init example 6     class SurveyQuestion {         var text: String         var response: String?         init(text: String) {             self.text = text         }         //Function         func ask() {             print(text)         }     }         //In ViewDidLoad         //Init example 1         let f = Fahrenheit()         print("The default temperature is \(f.temperature)° Fahrenheit")         // Prints "The default temperature is 32.0° Fahrenheit"              //Init example 2         print(Fahrenheit2().temperature)                  //Init example 3         let boilingPointOfWater = Celsius(fromFahrenheit: 210.0)         // boilingPointOfWater.temperatureInCelsius is 100.0         print(boilingPointOfWater)         let freezingPointOfWater = Celsius(fromKelvin: 270.15)         // freezingPointOfWater.temperatureInCelsius is 0.0         print(freezingPointOfWater)                  //Init example 4         let magenta = Color(red: 1.0, green: 0.0, blue: 1.0)         print(magenta)         let halfGray = Color(white: 0.5)         print(halfGray)                  //Init example 5         let bodyTemperature = Celsius2(37.0)         // bodyTemperature.temperatureInCelsius is 37.0         print(bodyTemperature)                  //Init example 6         let cheeseQuestion = SurveyQuestion(text: "Do you like cheese?")         cheeseQuestion.ask()         // Prints "Do you like cheese?"         cheeseQuestion.response = "Yes, I do like cheese."	https://docs.swift.org/swift-book/LanguageGuide/Initialization.html
FBSDK Integration tutorial			https://www.spaceotechnologies.com/integrate-facebook-sign-in-button-ios-app/
Get FB contacts list code			https://stackoverflow.com/questions/29428478/facebook-friends-list-api-for-swift-ios
Twitter Integration tutorial			https://www.brewit9.com/2017/10/twitter-login-integration-in-ios-using.html
LinkedIn Integration tutorial		https://www.appcoda.com/linkedin-sign-in/	http://www.theappguruz.com/blog/integrate-linkedin-sdk-in-ios
Push notifications tutorial			https://medium.com/ios-os-x-development/learn-master-%EF%B8%8F-ios-remote-push-notifications-in-2018-in-under-10-minutes-825ca6bee092
How to use two versions of Xcode’s tutorial			https://medium.com/@hacknicity/working-with-multiple-versions-of-xcode-e331c01aa6bc
SafeAreaLayout tutorial	https://medium.com/@kahseng.lee123/how-to-solve-the-most-common-interface-problems-when-adapting-apps-ui-for-iphone-x-44c0f3c80d84	https://medium.com/@kahseng.lee123/creating-custom-navigation-bar-tab-bar-for-iphone-x-f03b1e1827d3
	https://customersupport.doubledutch.me/hc/en-us/articles/360008823394-iOS-Client-Distribution-Process-for-New-Apps
UIView animations	https://www.journaldev.com/22104/ios-uiview-animations