CODEWITHSUNDEEP
iosswift
Fausto Checa
Fausto Checa

Reputation: 163

how to change the subscript in an array of arrays

I want to change subscript coordinates in an Array of Arrays [[Int]] in order to be able to address each value in a way similar to a spreadsheet, so assigning values, formulas across cells, etc.

Currently to address each value I need to subscript like table[2][1] = 12 or similar. I would like to subscript like a spreadsheet table[a][2] = 12, so that I can adapt long and complicated formulas in bigger speadsheets to similar tables using the same system used in spreadsheets.

The question is: how to change the subscript system in an efficient way? I send a simplified example to ilustrate the point

class ViewController: UIViewController {

var table = [[0,  1,  2,  3],
             [1, 32, 44, 25],
             [2, 12, 66, 43],
             [3,  3,  4,  5]]


override func viewDidLoad() {
    super.viewDidLoad()

    print(table[2][1])  // 12
    table[1][1] = 100
    table[3][3] = table[1][1] * table[3][1] * 10
    print(table[3][3])

    printArray(table: table, j: 3)


}

// MARK: - Function

func printArray(table: [[Int]], j:Int) {
    for i in 0...j {
        print(table[i])
    }
}

}

Upvotes: 0

Views: 380

Answers (1)

Andreas Oetjen
Andreas Oetjen

Reputation: 10199

The closest solution I found is to use enums, like here:

enum Column:Int {
    case a
    case b
    case c 
    // and so on
}

extension Array {
    subscript(col:Column) -> Element {
        get {
            return self[col.rawValue]
        }
        set(newValue) {
            self[col.rawValue] = newValue
        }
    }
}


var table = [[0,  1,  2,  3],
            [1, 32, 44, 25],
            [2, 12, 66, 43],
            [3,  3,  4,  5]]


table[.a][2] = 12
let val = table[.a][2]
print (val)

Nevertheless, there are two little drawbacks:

  • you first have hard-code all the "column" letters you want to access to the Column enum.
  • then, something like table[5][.c] and table[.a][.b] will also be allowed - so you could access the rows via letter, not only the columns

Upvotes: 2

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