A metatype type refers to the type of any type, including class types, structure types, enumeration types, and protocol types. The metatype of a class, structure, or enumeration type is the name of that type followed by .

What is a Metatype?

: a topotype or homeotype determined by the original author of its species.

How do you define a tuple in Swift?

According to Apple documentation on Swift Types: A tuple type is a comma-separated list of zero or more types, enclosed in parentheses. They're just a compound of other different types. Tuples may contain zero or more types, generally of a String , Integer , Bool as well as other tuples.

What are tuples in IOS?

According to apple, a tuple type is a comma-separated list of zero or more types, enclosed in parentheses. It's a miniature version of a struct. The type of a tuple is determined by the values it has. So ("tuple", 1, true) will be of type (String, Int, Bool) .

What is .self and .type in Swift?

In Swift, Self refers to a type – usually the current type in the current context. Just as lowercase self can mean any current object, uppercase Self can mean just about any current type.

Understanding associatedtype in Swift

What is INIT in Swift?

Swift init() Initialization is the process of preparing an instance of a class, structure, or enumeration for use. This process involves setting an initial value for each stored property on that instance and performing any other setup or initialization that is required before the new instance is ready for use.

What does .self do in Swift?

self is a property on the instance that refers to itself. It's used to access class, structure and enumeration instance within methods. When self is accessed in a type method ( static func or class func ), it refers to the actual type (rather than an instance).

What is tuples and set in Swift?

Remember: arrays keep the order and can have duplicates, sets are unordered and can't have duplicates, and tuples have a fixed number of values of fixed types inside them.

Why do we need tuples in Swift?

Tuples in Swift occupy the space between dictionaries and structures: they hold very specific types of data (like a struct) but can be created on the fly (like dictionaries). They are commonly used to return multiple values from a function call.

Does Swift have tuples?

Swift 4 also introduces Tuples type, which are used to group multiple values in a single compound Value. The values in a tuple can be of any type, and do not need to be of same type. For example, ("Tutorials Point", 123) is a tuple with two values, one of string Type, and other is integer type.

What is Inout Swift?

Swift inout parameters allow you to change an input passed into a function inside that function. As you may know, changing the value of a parameter passed into a function is not possible, as they are constants.

What is ARC in Swift?

Swift uses Automatic Reference Counting (ARC) to track and manage your app's memory usage. ... ARC automatically frees up the memory used by class instances when those instances are no longer needed.

What is lazy keyword in Swift?

A lazy var is a property whose initial value is not calculated until the first time it's called. ... A lazy stored property is a property whose initial value is not calculated until the first time it is used. You indicate a lazy stored property by writing the lazy modifier before its declaration.

What is classname self in Swift?

self is the swift metaType of MyClass. This object exposes init function and all the method defined in this class as curried method (read Instance Methods are Curried Functions in Swift). ... self to NSStringFromClass we get the mangled class name. String. self returns a similar to calling self on a swift class.

What is the difference between self and self in Swift?

The difference is that self is used in types and instances of types to refer to the type that it's in; and Self is used in protocols and extensions where the actual type is not yet known. In even simpler terms, self is used within an existing type; Self is used to refer to a type that Self is not yet in.

What type of object is self?

self is an object reference to the object itself, therefore, they are same. Python methods are not called in the context of the object itself. self in Python may be used to deal with custom object models or something.

Is a tuple an object?

A tuple is a collection of objects which ordered and immutable. Tuples are sequences, just like lists. The differences between tuples and lists are, the tuples cannot be changed unlike lists and tuples use parentheses, whereas lists use square brackets.

What are optionals in Swift?

An optional in Swift is basically a constant or variable that can hold a value OR no value. The value can or cannot be nil. It is denoted by appending a “?” after the type declaration.

Is tuple a dict?

A tuple can contain only the predefined number of values, in dictionary there is no such limitation. A tuple can contain different values with different datatype while a dictionary can contain only one datatype value at a time. Tuples are particularly useful for returning multiple values from a function.

What is guard in Swift?

Swift guard is defined as a statement that is used to transfer program control out of a scope if one or more conditions aren't met. What it means is that it is essentially a redirection or early exit of a statement or function to prevent crashing and incorrect data.

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 tuple and array?

Tuple A tuple is a grouping of unnamed, ordered values. Each value in a tuple does not need to be the same type. Array An array is mutable collection. They are very efficient to create, but must always be a single type.

What is backslash dot in Swift?

email with return \ , you get the compile-error "Expected expression path in Swift key path" , so this is a hint that this backslash-dot notation might have to do with something called a key path. From that documentation on key-path, we see that we could also have written \User.

What is weak self in Swift?

In Swift, we need to use weak self and unowned self to give ARC the required information between relationships in our code. Without using weak or unowned you're basically telling ARC that a certain “strong reference” is needed and you're preventing the reference count from going to zero.

What is static keyword in Swift?

Static variables are those variables whose values are shared among all the instance or object of a class. When we define any variable as static, it gets attached to a class rather than an object. ... You create static variable by appending static keyword in front of your variable declaration.