Why is my Swift loop failing with error “Can't form range with end < start”?

Question

I have a for loop that checks if a number is a factor of a number, then checks if that factor is prime, and then it adds it to an array. Depending on the original number, I wil

Answer 1

Using a simple solution you can make for loop reverse using Stride and -

func reverseArray(oldarray: [String]) -> [String] {
        var newArray = [String]()
        let len = oldarray.count
        for i in stride(from: len - 1, through: 0, by: -1)
        {    newArray.append(oldarray[i])
            print(i)
        }
        return newArray
    }

input :  print(reverseArray(oldarray: ["World", "Hello"]))

output : ["Hello", "World"]