What is designated initializer in Swift?
What is designated initializer in Swift?
A designated initializer is the primary initializer for a class. It must fully initialize all properties introduced by its class before calling a superclass initializer. A class can have more than one designated initializer.
What is init coder Swift?
The init?(coder:) initializer is a designated initializer that initializes a Task instance. Even though we implement the init?(coder:) method to conform to the NSCoding protocol, you won’t ever need to invoke this method directly. In Swift, there’s no such thing as protocol conformance or optional protocol methods.
What is NIB name in Swift?
Swift version: 5.4. NIBs and XIBs are files that describe user interfaces, and are built using Interface Builder. In fact, the acronym “NIB” comes from “NeXTSTEP Interface Builder”, and “XIB” from “Xcode Interface Builder”.
What is NIB name?
Nib names that include a platform-specific identifier such as ~iphone or ~ipad are loaded only on a device of the corresponding type. For example, a nib name of MyViewController~ipad. nib is loaded only on iPad. If your app supports both platform types, you must provide versions of your nib files for each platform.
What is required initializer in Swift?
Required initializers will be explained in this article. Write the required modifier before the definition of a class initializer to indicate that every subclass of the class must implement that initializer.
What are extensions in Swift?
Extensions add new functionality to an existing class, structure, enumeration, or protocol type. This includes the ability to extend types for which you don’t have access to the original source code (known as retroactive modeling). Extensions are similar to categories in Objective-C.
What is required init?
What is UINib in Swift?
A UINib object caches the contents of a nib file in memory, ready for unarchiving and instantiation. When your app needs to instantiate the contents of the nib file, it can do so without having to load the data from the nib file first, which improves performance.
What is a nib file in Swift?
A nib file is a special type of resource file that you use to store the user interfaces of iOS and Mac apps. A nib file is an Interface Builder document. iOS uses nibs as an implementation detail that supports storyboards, the iOS user interface design layout format.
What is NIB and Xib?
nib file, short for NeXT Interface Builder, or more recently, as a . xib file. When building an application, these files are copied into the app’s bundle and are loaded at run-time to provide the user interface for the application. xib files are compiled into nibs when the application is built.
Does a class need an init Swift?
Every class must have at least one designated initializer. In some cases, this requirement is satisfied by inheriting one or more designated initializers from a superclass, as described in Automatic Initializer Inheritance below.
How to create a convenience initializer for a UIViewController?
You can define a convenience initializer to call a designated initializer from the same class as the convenience initializer with some of the designated initializer’s parameters set to default values. You can also define a convenience initializer to create an instance of that class for a specific use case or input value type.
What are the rules for an initializer in Swift?
Before we continue, take note of a few “rules” for initializers: 1 A designated initializer must call a designated initializer from its immediate superclass 2 A convenience initializer must call another initializer from the same class 3 A convenience initializer must ultimately call a designated initializer
How to make an initializer for a viewcontroller?
Each time you call this method, it creates a new instance of the view controller using the init (coder:) method. Yet for programmatically created viewController or nib created viewControllers you can redirect that call as shown above. Convenience initializers are secondary, supporting initializers for a class.
Can a convenience initializer be used as a primary initializer?
Convenience initializers are secondary, supporting initializers for a class. You can define a convenience initializer to call a designated initializer from the same class as the convenience initializer with some of the designated initializer’s parameters set to default values.