Missing return in a function expected to return 'Double?'

Question

I\'m grinding through Apple\'s App Development with Swift book and I have been having a few issues with the Optionals sections.

I\'m getting stuck accessing a dictionary

Answer 1

As a pretty quick solution, all you have to do is to add return nil at the end of your function:

func priceCheck(name: String) -> Double? {
    let pricefinder = name
    if let name = stock[name] {
        print(name)
        if name > 0 {
            if let pricefinder = prices[pricefinder] {
                print(pricefinder)
                return pricefinder
            } else {
                return nil
            }
        }
    } else {
        return nil
    }

    // here we go:
    return nil
}

because at some point (name is not greater than 0), the function does not returns anything.

Also, note that you could implement your function -as a shorter version- as:

func priceCheck(name: String) -> Double? {
    let pricefinder = name
    if let name = stock[name], name > 0 {
        if let pricefinder = prices[pricefinder] {
            return pricefinder
        }
    }

    return nil
}

If the function returns nil at the end of it, there is no point of adding else { return nil } for each if; Or you could even use guard statement to achieve it as mentioned in Fogmeister`s answer.