Swift - Sort array similar to another - arrays

Question

In my tableview I get my data shown from these arrays:
var offersProduct = [String]()
var offersPrice = [String]()
var savings = [String]()
var shops = [String]()
var imageNames = [String]()
var exDates = [Int]()
var pickedIDs = [String]()
var setDates = [Int]()
Right now the data isn't sorted in any way. So I have 2 questions.
How do I sort arrays after date? Nearest to NSDate first.
I have the array of exDates, witch is an array of Int of timeIntervalSince1970. So i want the closest expiry date to get index 0 of the array.
How do I sort the other arrays like the first one?
So, lets say I have sorted exDates array, that gives me another problem, cause now the expiry date shown, doesn't match with the data from the other arrays. So I need to somehow sort the other arrays, by moving the data in from the same index as in the exDates array. How can that be done?
Hope someone can help.

Answer 1

Your problem is that you use separate entities where single/uniform entity should be used. To achieve what you are trying, you should switch to using class or struct which would encompass all the associated data.
If you proceed with the approach you currently adopt, you are guaranteed to have arbitrary bugs and performing dull operations to synchronize data across all your arrays. So, in essence, having multiple arrays instead of one array of specialized objects is a bad practice.
Consider refactoring your arrays:
struct Entity {
var offerProduct : String
var offerPrice : String
var savings : String
var shop : String
var imageName : String
var exDate : Int
var pickedID : String
var setDate : Int
}
var entities = [Entity]()
Then to sort single array of entities (once filled), you merely set necessary criteria, such as:
entities = entities.sorted(by: {$0.exDate > $1.exDate })

Answer 2

Make a structure:
struct Entry {
let product: String
let price: String
let saving: String
let shop: String
let imageName: String
let exDate: Int
let pickedID: String
let setDate: Int
}
Then use one array of these structures instead of several:
var entries = [Entry]()
You can sort this array easily by one of the structure's fields:
let expiryTimePoint = ...
entries = entries.sorted({
// compare absolute differences of intervals for sorting
return abs($0.exDate - expiryTimeInterval) > abs($1.exDate - expiryTimeInterval)
})