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Start your free trialEdwin Carrasquillo
10,315 PointsA question on extending a type while typecasting to another type
I think I could probably complete this using a function instead of a computed property, but I think the challenge expects a computed property. The issue being as seen by my code, the compiler is telling me I need to unwrap the variables while unwrapping the variables, but if I try and do that it complains that I'm using undeclared variables.
I'm stuck on this one and any help would be appreciated!
extension String {
var add: Int? {
guard let totalNumber = Int(self) + add else {
return nil
}
}
}
1 Answer
David Papandrew
8,386 PointsHmm...I haven't done this module yet, but from looking at the question it does state that it wants you to write a new method (i.e. function).
If that's the case, this solution will work (I submitted it and it passed):
// Enter your code below
extension String {
func add(value: Int) -> Int? {
if Int(self) != nil {
return Int(self)! + value
} else {
return nil
}
}
}
And to invoke the new string method:
"2".add(value: 10) // returns 12
"Dog".add(value: 10) // returns nil