Swift Docs - Closures Understanding Closures in Swift Closures are self-contained blocks of functionality that can be passed around and used in your code. In Swift, closures can capture and store references to variables and constants from the context in which they are defined. This capability is known as closing over those variables. What is a Closure? A closure in Swift is similar to a block in C and Objective-C, and to lambdas in other programming languages....
The Role of the Delegate Imagine you’re sitting in a restaurant. Here, you, the diner, are akin to a part of your application, let’s say a UIViewController. When you’re ready to order, you don’t go into the kitchen yourself. Instead, you tell the waiter what you’d like to eat. The waiter, in this scenario, is the ‘delegate’. In iOS, a delegate is an object that acts on behalf of another. It’s a way to extend and customize the behavior of various components....
What are assert and assertFailure? Assert and assertFailure are functions that allow you to check for a condition at runtime and stop the execution of your program if the condition is not met. You can use them to verify that your code is working as expected and catch any bugs or logic errors early. The syntax of assert is: assert(condition, message) where condition is a Boolean expression that evaluates to true or false, and message is an optional string that describes the error....
What is NSCache? NSCache is part of the Foundation framework in Swift and Objective-C. It’s designed to store and manage temporary, non-persistent key-value pairs in your application. The key differentiator of NSCache from other collections like Dictionary is its automatic eviction policy. When memory pressure occurs, NSCache can automatically remove objects from its storage based on various factors, such as access frequency or the object’s cost. class NSCache<KeyType, ObjectType> : NSObject where KeyType : AnyObject, ObjectType : AnyObject Swift Docs-NSCache...
What is a Subscript? A subscript is a shortcut for accessing the elements or values of a collection, sequence, or object by providing an index or key within square brackets. It allows you to define custom behavior for retrieving and setting values using a syntax similar to array or dictionary access. Why Use Subscripts? Subscripts are valuable in Swift for several reasons: Convenience: Subscripts provide a natural and intuitive way to access elements or values in custom types....
What are Sequence and IteratorProtocol Protocols? Sequence and IteratorProtocol are two related protocols that define a common interface for types that provide sequential, iterated access to their elements. A sequence is a list of values that you can step through one at a time, such as an array, a range, or a string. A sequence can also be infinite, such as the sequence of natural numbers or the sequence of Fibonacci numbers....
What is the Result Type? The Result type is an enumeration introduced in Swift to represent the result of an operation that can either succeed with a value or fail with an error. It is particularly useful for handling asynchronous tasks, such as network requests, file operations, or any other operation that might not produce an immediate result. Swift Docs-Result Type The Result type has two cases: enum Result<Success, Failure> where Failure: Error { case success(Success) case failure(Failure) } Success: This associated type represents the value that the operation produces when it succeeds....
What is Codable? Codable is a protocol that enables you to encode and decode data in various formats, such as JSON, XML, or plist. In this blog post, I will explain what Codable is, how to use it, and some common use cases. Codable is a type alias for two protocols: Encodable and Decodable. Encodable enables you to convert a type into a data representation, such as JSON. Decodable enables you to convert a data representation into a type, such as JSON....
What are property wrappers? Swift Docs-Property Wrappers Property wrappers are a powerful feature of Swift that allow you to add extra functionality to your properties without changing their declaration. In this blog post, I will explain what property wrappers are, how to use them, and some common use cases. Property wrappers are types that wrap a value and provide additional behavior or logic. They are declared with the @propertyWrapper attribute and have a wrappedValue property that holds the actual value....
Introduction Swift Docs - Associated Types Swift is a language that lets you write code in different ways, such as object-oriented, functional, and protocol-oriented. One of the features that makes Swift protocol-oriented is the ability to use associated types in protocols. What are associated types in Swift protocols? Associated types are a way to use placeholder types in protocols. Placeholder types are types that you don’t know yet, but you will know later when you use the protocol....