Swift: simple way to get the first leaf of multidimensional array

Question

Considering a non-empty multidimensional array that has no empty subarrays in it, how can I get the first leaf of it?

Currently, I'm using the following construct:

    let multidimensional = [[[[[[Int]]]]]]()
    let firstLeaf = multidimensional.first?.first?.first?.first?.first?.first
    print(firstLeaf)

Is there any simpler way of achieving the same result, i.e. taking the first leaf out of this array?

Answer 1

I'd create an extension for Array, and use recursion to loop array values until we reach the first element that is not an Array

extension Array {
    func firstLeaf() -> AnyObject? {
        var res : AnyObject? = self.first as? AnyObject
        if let leaf = res as? Array<Any>
        {
            res = leaf.firstLeaf()
        }

        return res
    }
}


print([[[[[[[String]]]]]]]().firstLeaf())       //Optional(<null>)
print([[[[[[[1,2,3]]]]]]].firstLeaf())          //Optional(1)
print([[[[[[["B", "A", "R"]]]]]]].firstLeaf())  //Optional("B")