Swift Language Declaring Dictionaries

Download Swift Language for free

Example

Dictionaries are an unordered collection of keys and values. Values relate to unique keys and must be of the same type.

When initializing a Dictionary the full syntax is as follows:

var books : Dictionary<Int, String> = Dictionary<Int, String>()

Although a more concise way of initializing:

var books = [Int: String]()
// or
var books: [Int: String] = [:]

Declare a dictionary with keys and values by specifying them in a comma separated list. The types can be inferred from the types of keys and values.

var books: [Int: String] = [1: "Book 1", 2: "Book 2"]
//books = [2: "Book 2", 1: "Book 1"] 
var otherBooks = [3: "Book 3", 4: "Book 4"]
//otherBooks = [3: "Book 3", 4: "Book 4"]
Accessing Values