For reading and writing you should use a location that is writeable, for example documents directory. The following code shows how to read and write a simple string. You can test it on a playground. Swift 3.x – 5.x let file = “file.txt” //this is the file. we will write to and read from it … Read more
Get nth character of a string in Swift programming language
An optional in Swift is a type that can hold either a value or no value. Optionals are written by appending a ? to any type: var name: String? = “Bertie” Optionals (along with Generics) are one of the most difficult Swift concepts to understand. Because of how they are written and used, it’s easy … Read more
Swift itself doesn’t use selectors — several design patterns that in Objective-C make use of selectors work differently in Swift. (For example, use optional chaining on protocol types or is/as tests instead of respondsToSelector:, and use closures wherever you can instead of performSelector: for better type/memory safety.) But there are still a number of important … Read more
tl;dr: Use the class constant approach if you are using Swift 1.2 or above and the nested struct approach if you need to support earlier versions. From my experience with Swift there are three approaches to implement the Singleton pattern that support lazy initialization and thread safety. Class constant class Singleton { static let sharedInstance … Read more
Why don’t protocols conform to themselves? Allowing protocols to conform to themselves in the general case is unsound. The problem lies with static protocol requirements. These include: static methods and properties Initialisers Associated types (although these currently prevent the use of a protocol as an actual type) We can access these requirements on a generic … Read more
Background: What’s an Optional? In Swift, Optional<Wrapped> is an option type: it can contain any value from the original (“Wrapped”) type, or no value at all (the special value nil). An optional value must be unwrapped before it can be used. Optional is a generic type, which means that Optional<Int> and Optional<String> are distinct types … Read more
So functions in swift are written like this: func <name> ( [param1, param2, …]) -> <return type> However, when the return type is Void you can disregard -> Void. So often you will see func <name> ( [param1, param2, …]) So in your case what you need is func getPickerDate () -> String { var … Read more