swift - Ordered Dictionary in JSON

Question

There are 3 string variables

public var userLoginId : String?
public var searchString : String?
public var tableName : String?

I have a dictionary:

let dict = ["userLoginId" : userLoginId, "searchString" : searchString,"tableName" : tableName]

Now I serialize it by JSON:

let data =  try! JSONSerialization.data(withJSONObject: dict, options :[])
let jsonstring = String(data:data, encoding:.utf8)!

In jsonstring, every time I get an unordered JSON like below:

"{"tableName":"null","userLoginId":"Dilip","searchString":"Tata"}"

How can I get in the same format in which I assigned value to dictionary?

Answer 1

Dictionaries are unordered

??But !

Since JSON is a String you can have an ordered JSON. You can use this library to parse the JSON in the original order. The usage is simple:

try JSON.parse(string: jsonString)

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Sorted Dictionary

From iOS 11 and macOS 10.13 there is a new option for JSONSerialization for sorting keys that you can use:

JSONSerialization.data(withJSONObject: json, options: [.sortedKeys])