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iOS Generics in Swift Generic Types Creating a Generic Type

Kristof Kocsis
Kristof Kocsis
15,455 Points
Posted by Kristof Kocsis
Kristof Kocsis
15,455 Points

Code can't compile but no error messages are thrown

I tried to complete this code challenge but I can't pass Task 4. I write my code in xcode and than copy it in the editor. My code works in a playground but the editor doesn't accept it. Am I missing something? Is there something more to the task that I didn't notice?

generics.swift 
struct Queue<Element> {

    var array: [Element] = [Element]()

    var isEmpty: Bool {
        if array.count == 0 {
            return true
        } else {
            return false
        }
    }

    var count: Int {
        var counter = 0
        for _ in array {
            counter += 1
        }

        return counter
    }

    mutating func enqueue(element: Element) -> [Element] {
        self.array.append(element)
        return array
    }
}

2 Answers

Joe Beltramo
Joe Beltramo
Courses Plus Student 22,191 Points

You are missing a key piece of the requirement omitting the external argument label

mutating func enqueue(_ element: Element) -> [Element] { // Be sure to omit it with _
    self.array.append(element)
    return array
}
Patrick Munemo
Patrick Munemo
14,892 Points
Patrick Munemo
Patrick Munemo
14,892 Points

struct Queue<Element> { var array = Element var isEmpty: Bool { if array.isEmpty { return true } else { return false } }

var count: Int {
    return array.count
}

mutating func enqueue(_ item: Element) {
    self.array.append(item)
}

mutating func dequeue() -> Element? {
    if self.array.isEmpty == false {
        return self.array.remove(at: 0)
    } else {
        return nil
    }

}

}