import UIKit

import Foundation


func printVowels(string: String) -> Int {

    let string = string
    var vowelCount = 0
    for letter in string {
        switch letter {
        case "a", "e", "i", "o", "u":
            vowelCount += 1
        default: "Error"
        }

    }
    return vowelCount
}
printVowels(string: "Alexandra")