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iOS Object-Oriented Swift 2.0 Class Inheritance Overriding Methods

Ryan Doyle
Ryan Doyle
8,587 Points
Posted by Ryan Doyle
Ryan Doyle
8,587 Points

Class Inheritance Stuggles

Ok, I am in this challenge, and I am totally stuck.

I do get the idea (kind of) of overriding the init in a subclass to initialize an instance of the subclass using the superclass, but I am really struggling in understanding when to use the "self." and when to use "super.". I think that might be what I messed up in the code, but even if by some random chance I got those right an it's something else, it would be helpful if someone could give a dummies version of what the difference is between using self. and parent. when using the subclasses...

classes.swift 
class Person {
    let firstName: String
    let lastName: String

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

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

// Enter your code below

class Doctor: Person {

    override init(firstName: String, lastName: String) {
        super.init(firstName: firstName, lastName: lastName)
        }

    self.getFullName() -> String {
    return "Dr. \(lastName)"
    }
}

let someDoctor = Doctor(firstName: "Doc", lastName: "Person")
someDoctor.getFullName()
sugabelly
sugabelly
2,524 Points

This confuses me too. Why do you need to override the init if the only thing you're changing in the subclass is what is returned by the function?

Why can't you just have override func without needing to have override init beforehand as well?

1 Answer

Alexander Smith
Alexander Smith
10,476 Points
Alexander Smith
Alexander Smith
10,476 Points

You've pretty much got it. Instead of self.getFullName(), override it and you're good. 

class Person {
    let firstName: String
    let lastName: String

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

    func getFullName() -> 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 getFullName() -> String {
    return "Dr. \(lastName)"
    }
}

let someDoctor = Doctor(firstName: "Doc", lastName: "Person")
someDoctor.getFullName()