Swift:声明一个空字典

我开始学习swift是通过苹果公司提供的swift上的iBook-The swift Programming Language。这本书说要创建一个空字典，应该使用[:]，就像声明数组为[]一样:

我声明一个空数组，如下所示:

let emptyArr = [] // or String[]()

但是在声明空字典时，我得到语法错误:

let emptyDict = [:]

如何声明一个空字典?

当前回答

您可以使用以下代码:

var d1 = Dictionary<Int, Int>()
var d2 = [Int: Int]()
var d3: Dictionary<Int, Int> = [Int : Int]()
var d4: [Int : Int] = [:]

其他回答

var dictList = String: swift中字典的字符串 var arrSectionTitle =字符串数组在swift

如果要创建具有任何类型的泛型字典

var dictionaryData = [AnyHashable:Any]()

在Swift中声明和初始化字典

字符串字典

var stringDict: [String: String] = [String: String]()

var stringDict: Dictionary<String, String> = Dictionary<String, String>()

Int字典

var stringDict: [String: Int] = [String: Int]()

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

AnyObject字典

var stringDict: [String: AnyObject] = [String: AnyObject]()

var stringDict: Dictionary<String, AnyObject> = Dictionary<String, AnyObject>()

字符串数组字典

var stringDict: [String: [String]] = [String: [String]]()

var stringDict: Dictionary<String, Array<String>> = Dictionary<String, Array<String>>()

字符串字典数组

var stringDict: [[String: String]] = [[String: String]]()

var stringDict: Array<Dictionary<String, String>> = Array<Dictionary<String, String>>()

var emptyDictionary = [String: String]()

var populatedDictionary = ["key1": "value1", "key2": "value2"]

注意:如果你打算改变字典的内容，那么就把它声明为一个变量(var)。你可以将一个空字典声明为常量(let)，但如果你想要改变它，这将是毫无意义的，因为常量值在初始化后不能被改变。

迅速:

var myDictionary = Dictionary<String, AnyObject>()

推荐文章