Create a 1-element array from a random element in a String array-CodePudding

I am trying to write a swift function that returns a single element array from a randomly-selected element of a String array (allFruits).

Goal:

let allFruits:[String] = ["Apples", "Oranges", "Pears", "Grapes", "Bananas"]

randomFruit = ["Apple"]

My progress:

let allFruits:[String] = ["Apples", "Oranges", "Pears", "Grapes", "Bananas"]

func randomFruit(arraySource:[String]) -> [String]{
    let randomItem = arraySource.randomElement()
    var singleArray:[String] = []
    return singleArray.append(contentsOf: randomItem)
}

I would then call this with randomFruit(arraySource: allFruits) to get ["Pears"]

The above return statement is giving me the error of:

Cannot convert return expression of type '()' to return type '[String]'

How can I return a random 1-element array from allFruits?

CodePudding user response：

randomItem in your code is an optional since .randomElement can return nil. This is confusing the .append() call at the end. The following should solve that issue.

func randomFruit(arraySource:[String]) -> [String]{
    if let item = arraySource.randomElement() {
        return [item]
    } else {
        return []
    }
}