CODEWITHSUNDEEP
arraysswiftmultidimensional-arraytypes
Mick
Mick

Reputation: 910

Creating multi-dimensional arrays containing different types in Swift

I want to create a multi-dimensional array in Swift and following on from this post on creating multi-dimensional arrays, I came up with:

var itemList: [[(String, Date, Double, Int)]] = []

let itemID = purchases["itemID"] as! String
let purchase_date = purchases["purchase_date"] as! Date
let purchase_date_ms = purchases["purchase_date_ms"] as! Double
let quantity = purchases["quantity"] as! Int

itemList.append([(itemID, purchase_date, purchase_date_ms, quantity)])

This all seems ok but when I try to get the data back out with:

var subPurchaseDate: Date
subPurchaseDate = itemList[0][1]

to try to read the "purchase_date" value from the array I get the error "Cannot assign value of type '(String, Date, Double, Int)' to type 'Date'", and

switch itemList[iloop][0] {
        ...
        }

gives "Expression pattern of type 'String' cannot match values of type '(String, Date, Double, Int)'"

Any clues as to why it's not taking the value/type of the element that I'm trying to specify in <array>[i][j] but seems to be trying to take <array>[i]? What am I not seeing?

Upvotes: 1

Views: 1307

Answers (1)

Sahil
Sahil

Reputation: 9226

You have stored tuple value inside array. so, access the contents of a tuple by providing the index position .

subPurchaseDate = itemList[0][1].0 // for string value
subPurchaseDate = itemList[0][1].1 // for date
subPurchaseDate = itemList[0][1].2 // for Double
subPurchaseDate = itemList[0][1].3 // for Int

You can also access using it's named value.

 var itemList: [[(stringValue: String, dateVal: Date, doubleValue: Double, intValue: Int)]] = []

// append elements in `itemList`
itemList.append([(stringValue: itemID, dateVal: purchase_date, doubleValue: purchase_date_ms, intValue: quantity)])

// access using it's named value

subPurchaseDate = itemList[0][1].stringValue // for string value
subPurchaseDate = itemList[0][1].dateVal // for date
subPurchaseDate = itemList[0][1].doubleValue // for Double
subPurchaseDate = itemList[0][1].intValue // for Int

Upvotes: 4

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