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iOS Object-Oriented Swift 2.0 Complex Data Structures Initializers and Self

Trevor Wood
Trevor Wood
17,828 Points
Posted by Trevor Wood
Trevor Wood
17,828 Points

Swift OOP question about structure

So I was watching the video here. https://teamtreehouse.com/library/objectoriented-swift-20/complex-data-structures/initializers-and-self

And this code came up. I'm going to write some comments int there, please correct me if they're wrong or need improvement

struct Point{
    //create constant
    let x: Int
    let y: Int
    //give constant a value
    init(x: Int, y: Int){//gets values from "Point(x: 5, y: 1)"
        //self.x is the constant I created// self is targeting "Point" and the x inside
        // the x following self.x is the value I passed through.
        self.x = x
        self.y = y
    }
}

Why would I choose to use this way over doing something like

func calculateArea(length: Int, width: Int) -> Int{
    let area = length * width
    return area
}

This way seems much less complicated and faster to read/write

3 Answers

Bill Merickel
Bill Merickel
11,420 Points

With that function, the only thing you can do is call the function with a set of values. If for instance, you wanted to create and save a rectangle, your function wouldn't work. You could only call an area. If you wanted to create a variable or constant rectangle, then you use your struct (or class). I hope that explains it, if not let me know!

Trevor Wood
Trevor Wood
17,828 Points
Trevor Wood
Trevor Wood
17,828 Points

Ah okay I see now what you mean. a Struct or Class can hold multiple data whereas a function can only execute and return code. Thanks!

Bill Merickel
Bill Merickel
11,420 Points
Bill Merickel
Bill Merickel
11,420 Points

No worries! Have fun learning Swift!

Trent Christofferson
Trent Christofferson
18,846 Points
Trent Christofferson
Trent Christofferson
18,846 Points

I dont think you can use dot notation with a function only a method