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Amelia Boli
1,953 PointsWhy would you set a default value for price when you initialize it later in the class?
I just don't understand why price is set to 0.0 when it is declared when price is part of the init method further down in the same class.
3 Answers
David Clausen
11,403 PointsHe's just walking through expanding the class to accept initializes so you can have a custom price. You can absolutely assign it in the init.
class Product {
var Price: Double
init (price: Double){
self.price= price
}
This should be acceptable and fine to use. Instead of deleting and going backwards it was easy to move forward with creating a initializer.
Robert Szabo
2,074 PointsHello,
I have the same question. But I do not understand that if the variable "price" is changed to a constant, he can still initialize it with the designated initializer. When I do this, I am getting an error: Cannot assign to 'price' in 'self'. It is only possible to have a default value when the price is a variable, not a constant. Isn't this correct?
class Product {
let title: String
let price: Double = 0.0
init(title: String, price: Double) {
self.title = title
self.price = price
}
}
So as the code in the example, I will have the error on the line 7.
Sain-R Edwards Jr.
1,853 PointsI think you're right Robert Szabo. I receive the same error when I change price to a constant. Weird.
Nic Laughter
2,692 PointsCame to the comments to find this. Glad I'm not missing something!
Nic Laughter
2,692 PointsNEVER MIND! I just realized you did the same thing I did, which was to neglect changing the class members from constants to variables. having "price" as a let, I deleted the 0.0 to get rid of the error, but then when Amit tells you to type "quadcopter.price = 199.99" I was getting another error, and that's when I realized the problem. Doing this will enable you to change the values of the members of class Product with subsequent commands.
Sain-R Edwards Jr.
1,853 PointsThanks for further explanation Nic Laughter
Amelia Boli
1,953 PointsAmelia Boli
1,953 PointsAre you saying that he simply didn't delete the 0.0 because he didn't want to go back and do so? There are several more videos which use this class and he never removes the 0.0 even though he always initializes the price after the first example. Is this a best practice?
David Clausen
11,403 PointsDavid Clausen
11,403 PointsThere is no cut and dry anwser to that. Apple documentation seems to suggest constructed initialization.
Honestly it depends on what you are doing with the variable. Lots see it in Object Oriented the purpose of the variable dictates where you initialize it.
If a variable in a class is immutable (never changes) amongst all the class then I do inline initialization. If its simply set to a default value among all instance of the class I do inline. If its going to be changed right away I do Do constructor.
In this case I think what he did is not considered beat practice. Since it's a price and you will always change it and the constructor requires the input of a price to create the instance then there is no need to set it to zero.