Swift Apprentice by Ray Wenderlich Chapter 9 A function that returns true if all of the values of a dictionary[String:Int] are unique.

Are there duplicates in Dictionary.swift

var dict = ["Eins" : 1, "Zwei": 2]


func isInvertible(_ dictionary: [String: Int]) -> Bool {
    var isItTrue = true
    var array : [Int] = []
    for numbers in dict.values {
        if array.contains(numbers) == false {
        array.append(numbers)
        }else{
            isItTrue = false
        }
    }
    return isItTrue
}


isInvertible(dict)