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iOS

Logan Cornelius
Logan Cornelius
16,876 Points
Posted by Logan Cornelius
Logan Cornelius
16,876 Points

How to initialize a property in a subclass that is unique from it's superclass?

class Roommate {

let name: String
var age: Int
var skills: [String]
var sayings: [String:String]

init(name:String, age:Int, skills: [String], sayings: [String:String]) {
    self.name = name
    self.age = age
    self.skills = skills
    self.sayings = sayings
}

}

class Pet: Roommate {

let isAnimal: Bool = true
var ownerIs: String //how do I initialize this since it is unique from the superclass

override init(name: String, age: Int, skills: [String], sayings: [String : String]) {
super.init(name: name, age: age, skills: skills, sayings: sayings)
}

}

2 Answers

Sarah Hurtgen
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.a{fill-rule:evenodd;}techdegree seal-36
Sarah Hurtgen
Treehouse Project Reviewer
Sarah Hurtgen
.a{fill-rule:evenodd;}techdegree seal-36
Sarah Hurtgen
Treehouse Project Reviewer

Are you wanting to have an initializer for "Pet" that allows you to fill in who the "ownerIs" as well as the original "name", "age", etc? One thing you could try is removing the word "override", and add the parameter "ownerIs: String" into the init(). 

init(name:String, age:Int, skills: [String], sayings: [String:String], ownerIs: String)

With this, I think you create a unique initializer that is specific to "Pet". In the body you would leave what you have already (the super.init), and would assign "ownerIs" to self, like you did for the variables in your "Roommate" init.

I'm not sure if that is quite what you were looking for, but I hope it helps!

Logan Cornelius
Logan Cornelius
16,876 Points
Logan Cornelius
Logan Cornelius
16,876 Points

Ok! This is working now! thank you!

class Pet: Roommate {

var isAnimal: Bool = true
var ownerIs: String


init(name: String, age: Int, skills: [String], sayings: [String : String], ownerIs: String) {
    self.ownerIs = ownerIs
    super.init(name: name, age: age, skills: skills, sayings: sayings)

}

}

So I have to incluce the unique property in the init, and set it equal to self, but then I don't include it in the super.init initializer because it is not found in the super class. That makes sense!

why do I take the override out fully since most of the properties are still being overridden?

Sarah Hurtgen
seal-mask
.a{fill-rule:evenodd;}techdegree seal-36
Sarah Hurtgen
Treehouse Project Reviewer
Sarah Hurtgen
.a{fill-rule:evenodd;}techdegree seal-36
Sarah Hurtgen
Treehouse Project Reviewer

Honestly, I'm pretty new to trying to understand classes/subclasses, so I'm not completely sure- but I think it's because instead of overriding the parent class init, you're adding a unique one. If you backspace the "ownerIs" parameter (leaving you with the inherited init), it will pop up that you need to need to use the word "override", but once you add a whole new parameter, it is a now a different init.

For example, if you weren't adding any new parameters and just wanted to override the init to do something different, you could do something like this: 

class Pet: Roommate {
    let isAnimal: Bool = true
    var ownerIs: String = "Bill"

    override init(name: String, age: Int, skills: [String], sayings: [String : String]) {
    print("Hello!")

    super.init(name: name, age: age, skills: skills, sayings: sayings)
    }
}

let puppy = Pet(name: "Spot", age: 1, skills: [], sayings: ["Bark" : "Woof!"])
// prints "Hello!"

So now when that original init is used, it does the added function of printing "Hello!"

There may be a way to override the parent init and actually change the parameters, but at this point, it is beyond my knowledge :)

Logan Cornelius
Logan Cornelius
16,876 Points
Logan Cornelius
Logan Cornelius
16,876 Points

Awesome! well thanks so much! I appreciate the help!