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Articles by Nitin Aggarwal
Page 8 of 14
What is the difference between a weak reference and an unowned reference?
Understanding iOS memory management is essential for iOS and macOS development. The concept of weak self and unowned self is challenging to understand, especially for beginners. ARC (Automatic Reference Counting) may have solved many problems for us. Swift still requires that you manage references a lot of the time when you are not working with value types. ARC or Automatic Reference Counting Automatic Reference Counting (ARC) is used for tracking and managing the app’s memory usage. In most cases, this means that memory management “just works” in Swift, and you don’t need to think about memory management yourself. ARC automatically ...
Read MoreWhat is the 'some' keyword in SwiftUI?
The "some" keyword in SwiftUI is used to indicate that a type conforms with a protocol, but the exact conformance is not specified. The AnyView type, a type-erased view that can represent any view conforming to the View protocol, is commonly used in association with it. SwiftUI defines some View as a type that, without identifying the specific view type, can represent any view that complies with the View protocol. This enables more generalized and adaptable code. In other words, some keyword is used to declare Opaque types. In the Swift 5.1 version, this is introduced with the support of ...
Read MoreWhat is the 'open' keyword in Swift?
In swift, we have three keywords - Open, Public, and Final keyword. All these three words have different properties that help us understand whether the code can be extended to another module or not making the code easy to reuse. We will learn about the keywords' properties in this article.Example Here's an example of how the open keyword is used in a class definition import Foundation open class Person { var firstName: String? var lastName: String? var age: Int? var address: String? } class Student: Person ...
Read MoreWhat Is a Completion Handler in Swift?
In swift, the completion handler is a block of code that is used to perform and handle the completion state of a task. For example, completion handlers are very commonly used in network requests using URLSession class. Basically, the completion handler is passed as a function argument and called when the task is completed. It does not impact whether the task is completed successfully or not. You can use the completion handler to perform different actions in your iOS applications. There are some common practices to implement the completion handler such as returning status after cleaning up the unused resources ...
Read MoreWhat does init() do in Swift?
The init() method in Swift is used to initialize the objects of a class. When an object is created using the function Object() { [native code] } of the class, it is automatically called and establishes the object's initial state. To offer customized initialization behavior, such as establishing default values for properties or carrying out other setup chores, the init() method can be changed. Without returning any values, the function is sometimes used to initialize objects with some values. The class's designated initializer, the init() method, should be used to create objects of that class. Here is an example of ...
Read MoreWhat are the Adapter and Memento Patterns in Swift?
In this article, you will learn about both the pattern in the Swift language. Also, you will see what are advantages of using these patterns. You will see examples of how you can adopt these patterns in your projects. Using the adapter pattern, you can design a system that allows two different interfaces to work together or communicate between them. You can implement this design pattern with the class or structure by conforming to a certain protocol. Then, you can use an instance of that class or struct to interact with an object that conforms to a different protocol. Using ...
Read MoreUsing isKindOfClass with Swift
In this article, you are going to learn how to use isKindOfClass in swift with some different examples. It is required many times you need to check the type of a class to perform specific code accordingly. What is “isKindOfClass”? The isKind(of:) method can be used for checking the object type. You can check if an object is an instance of a given type. You can check it for a class or subclass depending on the boolean value returned. In Swift 5, the isKind(of:) method has been replaced by the is an operator and the is a keyword. The is ...
Read MoreSwift: Test class type in the switch statement
In Swift, you can use the is keyword to test the class type of an object in a switch statement. Also, you will some examples of how to typecast an object to the expected type. Here is an example to test primitive data types In this example, you will check the type for primitive data types such as String, Int, Double, etc. You can use the switch statement to check multiple conditions like the below −Example import Foundation func checkType(_ value: Any) { switch value { case is String: print("The value ...
Read MoreReading a JSON file using Swift
In this article, we will see some examples of how we can read the JSON file using JSONSerialization and JSONDecoder classes. Nowadays, these classes are used in most iOS applications to work with JSON files. You can use the JSONSerialization class to read the JSON file in the Swift language. In order to read a json file, first you will require to convert it into a string or data object. After that, you can pass the string or data object to JSONSerialization class to convert it into a dictionary or array object. JSONSerialization The Foundation framework for iOS and macOS ...
Read MoreRead and write a string from a text file
In Swift, you can read and write a string from a text file using the String(contentsOfFile:) and write(toFile:atomically:encoding:) methods of the String class. You will see some examples of file reading and writing in Swift. String(contentsOfFile:) A class method for creating a string from a file's content is provided by the String class. This method is an initializer where the path to the file must be given. For instance, you can read the contents of local files by passing the path to the main bundle. A new string containing the file's content is returned by this procedure. Keep in mind ...
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