Avoid duplicates while adding in dictionary - ios

Question

I have a dictionary in which I'm adding values like so...
var mydictionary = ["id": "", "quantity": "","sellingPrice":""] as [String : Any]
dictionary["id"] = product?.id
dictionary["quantity"] = product?.quantity
dictionary["sellingPrice"] = product?.theRate
And these values I added to an array like so...
self.arrayOfDictionary.append(mydictionary)
But if arrayOfDictionary already contains mydictionary, I don't want to add it. Else, I want to add it.
The basic idea here is to add data from collection view items to array of dictionary. When I click on the buttons that I have on each collection view item the data on it is added to an array of dict. while at the same time showing those data in a tableviewcell. But when I navigate back from the tableview & visit the collectionview items again and click on some other collecn.view item, so as to add them to the array of dictionary as before, then the item that was added initially to the array of dictionary gets added again. This has to be somehow prevented.
As suggested by another SO user something like this was tried to prevent this duplication...
if self.arrayOfDictionary.contains(where: { (dict) -> Bool in
"\(dict["id"] ?? "")" != "\(dictionary["id"] ?? "")"}) {
self.arrayOfDictionary.append(dictionary)
}
But this doesn't seem to work. With this nothing is added to the array and its totally empty. Hope somebody can help...

Answer 1

Try this code to avoid duplication
I hope "id" value will be unique in your dictionary.
var mydictionary = ["id": "1", "quantity": "","sellingPrice":""] as [String : Any]
var arrayOfDictionary = [Dictionary<String, Any>]() //declare this globally
let arrValue = arrayOfDictionary.filter{ (($0["id"]!) as! String).range(of: mydictionary["id"]! as! String, options: [.diacriticInsensitive, .caseInsensitive]) != nil }
if arrValue.count == 0 {
arrayOfDictionary.append(mydictionary)
}

Answer 2

I've got better idea then every time you perform loop to check unique ness.
Maintain one Bool array of same size of your collectionView Items array with predefined false values each.
When you click on button of collection View item, change flag of Bool array with same index. And simultaneously you can disable the button also(if you want). Otherwise whenever user clicks on button, just check flag from Bool array and add Dictionary to new array as needed.
Here, your new array will be performed and you will same process and time of looping also.

Answer 3

One way to approach the problem could be to construct a structure which contains product details:
/// Details Of A Product
struct ProductDetails{
var id: String!
var quantity: Int!
var sellingPrice: Int!
}
Then create a dictionary which stores the product details with the key being the "ID" e.g:
var products = [String: ProductDetails]()
You could then create a product like so:
let productA = ProductDetails(id: "1", quantity: 100, sellingPrice: 10)
To add a unique product to your dictionary you could use a function like this:
/// Adds A Product To The Products Dictionary
///
/// - Parameter product: ProductDetails
func addProductDetails(_ product: ProductDetails){
//1. If A Product Exists Ignore It
if products[product.id] != nil{
print("Product With ID \(product.id!) Already Exists")
}else{
//2. It Doesn't Exist So Add It To The Dictionary
products[product.id] = product
}
}
I tested this quickly and it won't allow products which have duplicate ID's. although of course you could change the parameter as needed.