How do enums work in Swift?
The syntax for enumerations is quite simple: You use the enum keyword to declare an enumeration, i.e. enum name { body } , much like declaring classes. In the enum body, you can include a number of cases with the case keyword. An enum’s cases are the different values that it has, such as the above ice cream flavors.
What is fast enumeration in Swift?
Fast enumeration is a language feature that allows you to efficiently and safely enumerate over the contents of a collection using a concise syntax.
What is lazy property in Swift?
A lazy stored property is a property whose initial value isn’t calculated until the first time it’s used. You must always declare a lazy property as a variable (with the var keyword), because its initial value might not be retrieved until after instance initialization completes.
What are the disadvantages of enumeration?
Disadvantages of using Enum as a singleton:
- Coding Constraints. In regular classes, there are things that can be achieved but prohibited in enum classes. Accessing a static field in the constructor, for example.
- Serializability. For singletons, it is very common to be stateful.
Is enum or constant better?
Enums are lists of constants. When you need a predefined list of values which do represent some kind of numeric or textual data, you should use an enum. You should always use enums when a variable (especially a method parameter) can only take one out of a small set of possible values.
What is enum in Swift Swift?
Swift – Enumerations. An enumeration is a user-defined data type which consists of set of related values. Keyword enum is used to defined enumerated data type.
What are associated values in Swift enumerations?
This additional information is called an associated value, and it varies each time you use that case as a value in your code. You can define Swift enumerations to store associated values of any given type, and the value types can be different for each case of the enumeration if needed.
How do you iterate over an enumeration in Swift?
Iterating over Enumeration Cases¶. For some enumerations, it’s useful to have a collection of all of that enumeration’s cases. You enable this by writing : CaseIterable after the enumeration’s name. Swift exposes a collection of all the cases as an allCases property of the enumeration type.
What is an enumeration in C?
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. If you are familiar with C, you will know that C enumerations assign related names to a set of integer values.