What is wrong in this

Hi,

It seems like you're mixing up several things.

• In your function you must switch on the day variable, not dayOfTheWeek which is the function name.
• When calling your function at the end you must give the aNumber variable as parameter.

This code:

var aNumber = 7

func dayOfTheWeek(day: Int) {

    switch day {

    case 2:

        print("Monday")

    case 3:

        print("Tuesday")

    case 4:

        print("Wednesday")

    case 5:

        print("Thursday")

    case 6:

        print("Friday")

    case 7:

        print("Saturday")

    case 8:

        print("Sunday")

    default:

        print("Error")

    }

}

dayOfTheWeek(day: aNumber)

Will print the following output: "Saturday".

What is wrong in this

First, the formatting… 😉

var aNumber =  Int(readLine()!)!
func dayOfTheWeek(day: Int) {
    
    switch dayOfTheWeek {
    case 2:
        print("Monday")
    case 3:
        print("Tuesday")
    case 4:
        print("Wednesday")
    case 5:
        print("Thursday")
    case 6:
        print("Friday")
    case 7:
        print("Saturday")
    case 8:
        print("Sunday")
    default:
        print("Error")
    }
}
dayOfTheWeek(day: <#Int#>)

This code is not very robust. Unwrapping without checking for nil may cause crashes.

For instance, you'd better write:

var aNumber =  Int(readLine() ?? "0") ?? 0

You cannot use the func name in the switch, in addition it would be a wrongType (a func () -> Void, and not an Int for the switch)

Does your week really starts at 2 ? It is probably 0 (maybe 1) ; in anglo saxon world, first day is sunday (0)

So, at the end your code should look like this:

var aNumber =  Int(readLine() ?? "0") ?? 10
func dayOfTheWeek(day: Int) {
    
    switch day {
    case 1:  // if first day is 1 ; 
        print("Monday")
    case 2:
        print("Tuesday")
    case 3:
        print("Wednesday")
    case 4:
        print("Thursday")
    case 5:
        print("Friday")
    case 6:
        print("Saturday")
    case 7:
        print("Sunday")
    default:
        print("Error")
    }
}

print(dayOfTheWeek(day: aNumber))