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iOS

Posted by Mark El-Lamaa
Mark El-Lamaa
1,634 Points

This isn't technically from treehouse but some help will be appreciated...

struct Size { var width = 0.0, height = 0.0 } struct Point { var x = 0.0, y = 0.0 }

Rect {

var origin = Point()
var size = Size()
init() {}
init(origin: Point, size: Size) {
    self.origin = origin
    self.size = size
}

}

my question is what is the point of the lines self.origin=origin and self.size=size at the end? Something got to do with initialisation i know but doesn't the init(origin: Point, size: Size) initialise that code already?!?

1 Answer

Stone Preston
Stone Preston
42,016 Points

an initializer is just a special function. you pass in arguments, and those arguments are used to set the values of properties of that class/struct.

in your Rect initializer, you initialize the origin and size properties using the arguments that are passed in to the function.

init(origin: Point, size: Size) {
        self.origin = origin
        self.size = size
    }

when the init method is called, you pass in the two origin and size arguments. then, the values of the origin and size properties of the rect struct are set using those values.

since the init parameters are named the same as the properties (the properties are named origin and size, but so are the parameters), you have to use self.origin to reference the property, since origin refers to the paramter

Mark El-Lamaa
Mark El-Lamaa
1,634 Points

thank you makes sense now