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iOS Functions in Swift Adding Power to Functions Returning Complex Values

Michael Liang
Michael Liang
1,209 Points
Posted by Michael Liang
Michael Liang
1,209 Points

Stuck in the last question in the course "Functions in Swift 3". Help please.Many thanks

In this challenge, we have the following geographical coordinates

Eiffel Tower - lat: 48.8582, lon: 2.2945 Great Pyramid - lat: 29.9792, lon: 31.1344 Sydney Opera House - lat: 33.8587, lon: 151.2140

Declare a function named coordinates that takes a single parameter of type String, with an external name for, a local name of location, and returns a tuple containing two Double values (Note: You do not have to name the return values). For example, if I use your function and pass in the string "Eiffel Tower" as an argument, I should get (48.8582, 2.2945) as the value. If a string is passed in that doesn’t match the set above, return (0,0)

Michael Liang
Michael Liang
1,209 Points
Michael Liang
Michael Liang
1,209 Points

I don't know what should I type in the body of the function.Should I add a swicth?

2 Answers

thecompanion
thecompanion
11,729 Points

Yes, you could use a switch, since you've got a defined set of cases you want to evaluate for a match. So your switch statement should have cases for each of the locations. You'd pass a string into the function parameter, which then switches over the cases you define. If there's a match, you set the switch to return a tuple made up of the lat and lon values.

Michael Liang
Michael Liang
1,209 Points
Michael Liang
Michael Liang
1,209 Points

func coordinates(for location: String) -> (Double, Double) { swicth location { case " Eifeel Tower": 48.8582, 2.2945 case "Great Pyramid": 29.9792, 31.1344 case "Sydney Opera House": 33.8587, 151.2140 } return (Double, Double) }

This is what I did,however it can not be compilde.Could you help me more? thanks a lot

thecompanion
thecompanion
11,729 Points
thecompanion
thecompanion
11,729 Points

seems like your syntax might be off--you need to tell each case to return something in order for the code to work. Something like this:

func coordinates(location: String) -> (lat: Double, lon: Double) {
    switch location {
    case "Eiffel Tower":
        return (48.8582, 2.2945)
    case "Great Pyramid":
        return (29.9792, 31.1344)
    case "Sydney Opera House":
        return (33.8587, 151.2140)
    default:
        print("error--location not found.")
        return (0, 0)    
    }
}