I've reached a point in an application where I need to initialize some coordinates to an array and I wound up using nested for-in loops to accomplish the task.
Is there is a better way to accomplish this?
class Coord {
let xVal : Int
let yVal : Int
init(x: Int, y: Int) {
xVal = x
yVal = y
}
}
var coord = [Coord]()
for xVal in 0...20 {
for yVal in 0...20 {
coord.append(Coord(x: xVal, y: yVal))
}
}
What you have is fine. If you wanted to use a functional approach and avoid making coord be mutable you could use flatMap and map:
let indexes = 0...20
let coord = indexes.flatMap { (xVal:Int) -> [Coord] in
indexes.map { (yVal:Int) -> Coord in
Coord(x: xVal, y: yVal)
}
}
If you are familiar with lambda expressions then you may know that this can be simplified to this:
let indexes = 0...20
let coord = indexes.flatMap { x in indexes.map { Coord(x: x, y: $0) } }
If all you are doing with Coord is storing coordinates, you may consider just using Tuples:
let coord = indexes.flatMap { xVal in indexes.map { yVal in (xVal, yVal) }}
