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iOS Object-Oriented Swift Class Inheritance Overriding Methods

Michael Williams
PLUS
Michael Williams
Courses Plus Student 8,059 Points
Posted by Michael Williams
Michael Williams
Courses Plus Student 8,059 Points

Swift Inheritance: overriding func not working

Following are some errors from the code that follows. First, I understand what's going on with the last error: I'm returning something when it's expecting me to return nothing because it hasn't been defined. To fix it, I need to add a return value for the function I'm overriding. However, the question is why do I still have to have a return value that's been inherited? Shouldn't that be implied? 

swift_lint.swift:40:19: error: method does not override any method from its superclass     override func fullName(){ 

^ swift_lint.swift:29:8: note: potential overridden instance method 'fullName()' here   func fullName() -> String {

^ swift_lint.swift:41:16: error: unexpected non-void return value in void function         return "Dr. \(lastName)"                ^~~~~~~~~~~~~~~~~

class Person {
  let firstName: String
  let lastName: String 

  init(firstName: String, lastName: String) {
    self.firstName = firstName
    self.lastName = lastName
  }

  func fullName() -> String {
    return "\(firstName) \(lastName)"
  }
}

// Enter your code below
class Doctor: Person {
    override init(firstName: String, lastName: String) {
        super.init(firstName: firstName, lastName: lastName)
    }

    override func fullName() String {
        return "Dr. \(lastName)"
    }

}

let someDoctor = Doctor(firstName: "Turd", lastName: "Ferguson")

2 Answers

tromben98
tromben98
13,273 Points
tromben98
tromben98
13,273 Points

Hi Michael!

If you look through the function you can notice that you forgot to mark the return type with the return arrow :

->

class Person {
  let firstName: String
  let lastName: String 

  init(firstName: String, lastName: String) {
    self.firstName = firstName
    self.lastName = lastName
  }

  func fullName() -> String {
    return "\(firstName) \(lastName)"
  }
}

// Enter your code below
class Doctor: Person {
    override init(firstName: String, lastName: String) {
        super.init(firstName: firstName, lastName: lastName)
    }
                                         // Look here!!!!!!!!!!
    override func fullName()  -> String {
        return "Dr. \(lastName)"
    }

}

let someDoctor = Doctor(firstName: "Turd", lastName: "Ferguson")
Michael Williams
PLUS
Michael Williams
Courses Plus Student 8,059 Points
Michael Williams
Michael Williams
Courses Plus Student 8,059 Points

Hi there. Thanks for your help. I understand that the return portion is missing, but my question is why does it have to be there if we're inheriting it from the superclass? Because writing out the return type is repeating code.

Jeffrey Hallett
Jeffrey Hallett
Courses Plus Student 1,619 Points

I am pretty sure this is because you need to print the "Dr."