Swift Style

Constructing Collections with Literals

Most Swift types require constructors or factory methods to create instances:

let instance = TypeConstructor(arguments...)

However, most collections support literal initialization. When available, prefer literal initialization to constructors, especially for array and dictionary literals:

let array: [String] = [] // yes
let dictionary: [AnyHashable: Any] = [:] // yes
let aSet: Set<String> = [] // yes
let array = [String]() // no
let array = Array<String>() // no
let dictionary = [AnyHashable: Any]() // no
let dictionary = Dictionary<AnyHashable: Any>() // no
let aSet = Set<String>() // no

This is a guideline, not an absolute. Using ...