Determine Size of Multidimensional Array in Swift

Question

I am new to Swift and am struggling to work out how to determine the size of a multidimensional array.

I can use the count function for single arrays, however when i create a matrix/multidimensional array, the output for the count call just gives a single value.

var a = [[1,2,3],[3,4,5]]
var c: Int
c = a.count
print(c)

2

The above matrix 'a' clearly has 2 rows and 3 columns, is there any way to output this correct size.

In Matlab this is a simple task with the following line of code,

a = [1,2,3;3,4,5]
size(a)
ans =
2 3

Is there a simple equivalent in Swift

I have looked high and low for a solution and cant seem to find exactly what i am after.

Thanks
- HB

Answer 1

Because 2D arrays in swift can have subarrays with different lengths. There is no "matrix" type.

let arr = [
    [1,2,3,4,5],
    [1,2,3],
    [2,3,4,5],
]

So the concept of "rows" and "columns" does not exist. There's only count.

If you want to count all the elements in the subarrays, (in the above case, 12), you can flat map it and then count:

arr.flatMap { $0 }.count

If you are sure that your array is a matrix, you can do this:

let rows = arr.count
let columns = arr[0].count // 0 is an arbitrary value