Swift : Why super. init Is Called After setting all self Properties. Once the initial state for every stored property has been determined, the second phase begins, and each class is given the opportunity to customize its stored properties further before the new instance is considered ready for use.
Enums in swift. An enumeration defines a common type for a group of related values and enables you to work with those values in a type-safe way within your code. Enumerations in Swift are much more flexible, and do not have to provide a value for each case of the enumeration.
self is a property on the instance that refers to itself. It's used to access class, structure and enumeration instance within methods. Swift allows to omit self when you want to access instances properties.
Some additional features of Swift include:
- Closures unified with function pointers.
- Tuples and multiple return values.
- Generics.
- Fast and concise iteration over a range or collection.
- Structs that support methods, extensions, and protocols.
- Functional programming patterns, e.g., map and filter.
A data type is the type of data (value) a variable or constant can store in it. For example, in the article Swift Variables and Constants, you created a variable and a constant to store string data in the memory. This data can be a text/string ("Hello") or a number (12.45) or just bits (0 &1).
A protocol defines a blueprint of methods, properties, and other requirements that suit a particular task or piece of functionality. The protocol can then be adopted by a class, structure, or enumeration to provide an actual implementation of those requirements.
init before performing any additional init actions. Required initializers, on the other hand, are not the same as designated. Required Initializers. Write the required modifier before the definition of a class initializer to indicate that every subclass of the class must implement that initializer.
An initializer is a special type of method in a Swift struct, class, or enum that is responsible for making sure a newly created instance of the struct, class, or enum is fully initialized before they are ready to be used. They play the same role as that of a “constructor” in Java and Groovy.
Stored Properties. In its simplest form, a stored property is a constant or variable that is stored as part of an instance of a particular class or structure. Stored properties can be either variable stored properties (introduced by the var keyword) or constant stored properties (introduced by the let keyword).
AnyObject and relaxed type-safety
AnyObject is a protocol that can represent an instance of any class type. It also has a more general counterpart, Any , which can represent any type at all (including structs and enums). It fails with the error 'AnyObject' does not have a member named 'saySomething()'.Object Oriented Programming
- Instantiation in Swift. Instantiation is used to create an object instance from a class (also known as initialization).
- Syntax. var classObject = className(paramName: paramValue, paramName2: paramValue2)
- Notes. External parameter names must be provided to instantiate an object.
- Example.
init is idiomatic Swift way of creating new objects of a class. Adding convenience initializers is the right choice in most cases when you want to add a shortcut to class's main (designated) initializer. However, in your case, they are completely unnecessary, because Swift supports default argument values.
A designated initializer must ensure that all of the properties introduced by its class are initialized before it delegates up to a superclass initializer. As mentioned above, the memory for an object is only considered fully initialized once the initial state of all of its stored properties is known.
The init?(coder:) initializer is a designated initializer that initializes a Task instance. The same is true for encode(with:) , which encodes an instance of the Task class. The required keyword prefixing the init?(coder:) method indicates that every subclass of the Task class needs to implement this method.
Singleton in Swift. Singleton is a creational design pattern, which ensures that only one object of its kind exists and provides a single point of access to it for any other code. Singleton has almost the same pros and cons as global variables. Although they're super-handy, they break the modularity of your code.
