How to create the specified data structure in swift ios? - ios

Question

I am trying to create a particular data structure as specified below in Swift.
[{"productId":1,"qty":3},{"productId":2,"qty":1},{"productId":3,"qty":5},{"productId":4,"qty":30},{"productId":5,"qty":13}]
Can some one guide me how to achive it..... I need to add and remove the data structure.
Thanks in advance.....

Answer 1

It is an Array of Dictionaries.
Define it like this :
var dataStructure = [[String: Any]]()
To add something :
var newData = [String: Any]()
newData["productId"] = 1
newData["qty"] = 1
dataStructure.append(newData)
To delete :
dataStructure.remove(at: indexYouWantTodeleteInInt)

Answer 2

It is called as dictionary in swift.
The declaration part can be as follows:
var params: [String:Any]
We can also use like:
var params: [String:Any] = ["user_id" : AppConfiguration.current.user_id]
Now to add key-value pair in it you can do as follows:
params["form_id"] = form_id!
params["parent_category_id"] = id
params["device_token"] = getDeviceToken()
params["app_version"] = APP_VERSION
params["app_device_type"] = originalDeviceType
to remove a key-value pair:
params.removeValue(forKey: "parent_category_id")
to update any value of particular key:
params.updateValue("10", forKey: "form_id")
if the above key is already present it updates the value and if not then it adds a new key to the dictionary
The Above explained part is dictionary. Now you need the data-structure as array of dictionary so you need to declare as
var params: [[String:Any]]
you can perform all the operations you can perform on an array but the value you will get at a particular index will be of type dictionary which I explained above.
Hope this helps you understand what is dictionary and what is array of dictionaries.
In your case you can also write [String: Int] instead of `[String:Any]' but it will restrict you to only have integer values with respect to the keys.

Answer 3

Swift developers usually use Structs in order to create a data structure from a JSON reponse. From Swift 4, JSON parsing has become very easy. Thanks to Codable protocols.
From the above given answer, you can create something like this.
MyStruct.Swift
import Foundation
typealias MyStruct = [[String: Int]]
You can then parse by calling the following method.
let myStruct = try? JSONDecoder().decode(MyStruct.self, from: jsonData)
You can add value by using this.
var newProduct = [String: Any]()
newProduct["productId"] = 941
newProduct["qty"] = 2
myStruct.append(newProduct)
To remove the data
myStruct.remove(at:"Some index")