I've seen so many different examples on how to do this but none of them seem to show an answer that I really need. So I know how to declare a multidimensional array of type bool.
var foo:[[Bool]] = []
However I cannot figure out how to declare this of type 10 x 10. Every example I look up just appends to an empty set, so how do I initialize this variable to be a 10x10 where each spot is considered a boolean?
You can also do it with this oneliner:
var foo = Array(repeating: Array(repeating: false, count: 10), count: 10)
The other answers work, but you could use Swift generics, subscripting, and optionals to make a generically typed 2D array class:
class Array2D<T> {
let columns: Int
let rows: Int
var array: Array<T?>
init(columns: Int, rows: Int) {
self.columns = columns
self.rows = rows
array = Array<T?>(count:rows * columns, repeatedValue: nil)
}
subscript(column: Int, row: Int) -> T? {
get {
return array[(row * columns) + column]
}
set(newValue) {
array[(row * columns) + column] = newValue
}
}
}
(You could also make this a struct, declaring mutating.)
Usage:
var boolArray = Array2D<Bool>(columns: 10, rows: 10)
boolArray[4, 5] = true
let foo = boolArray[4, 5]
// foo is a Bool?, and needs to be unwrapped
For Swift 3.1:
var foo: [[Bool]] = Array(repeating: Array(repeating: false, count: 10), count: 10)
As a one-liner, you can initialize like this with computed values assigned:
var foo = (0..<10).map { _ in (0..<10).map { $0 % 2 == 0 } }
Or
var bar = (0..<10).map { a in (0..<10).map { b in (a + b) % 3 == 0 } }
