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
我通常用
var dictionary:[String:String] = [:]
dictionary.removeAll()
其他回答
斯威夫特4
let dicc = NSDictionary()
//MARK: - This is empty dictionary
let dic = ["":""]
//MARK:- This is variable dic means if you want to put variable
let dic2 = ["":"", "":"", "":""]
//MARK:- Variable example
let dic3 = ["name":"Shakeel Ahmed", "imageurl":"https://abc?abc.abc/etc", "address":"Rawalpindi Pakistan"]
//MARK: - This is 2nd Variable Example dictionary
let dic4 = ["name": variablename, "city": variablecity, "zip": variablezip]
//MARK:- Dictionary String with Any Object
var dic5a = [String: String]()
//MARK:- Put values in dic
var dic5a = ["key1": "value", "key2":"value2", "key3":"value3"]
var dic5b = [String:AnyObject]()
dic5b = ["name": fullname, "imageurl": imgurl, "language": imgurl] as [String : AnyObject]
or
//MARK:- Dictionary String with Any Object
let dic5 = ["name": fullname, "imageurl": imgurl, "language": imgurl] as [String : AnyObject]
//MARK:- More Easy Way
let dic6a = NSDictionary()
let dic6b = NSMutalbeDictionary()
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] = [:]
用这个会有用的。
var emptyDict = [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。
如果要创建具有任何类型的泛型字典
var dictionaryData = [AnyHashable:Any]()
