Swift 4

Question

I've got this code from another course:

struct markStruct {
var mark1: Int
var mark2: Int
var mark3: Int

init(mark1: Int, mark2: Int, mark3: Int) {
self.mark1 = mark1
self.mark2 = mark2
self.mark3 = mark3
}
}

var marks = markStruct(mark1: 98, mark2: 96, mark3:100)
print(marks.mark1)
print(marks.mark2)
print(marks.mark3)

here in code, why this block of code is used when it is printing the result without it?

init(mark1: Int, mark2: Int, mark3: Int) {
self.mark1 = mark1
self.mark2 = mark2
self.mark3 = mark3
}

Answer 1

'init' is a special method used for initialization of instance when creating from struct or class.

So 1st statement: 'var marks = markStruct(98,96,100)' mean creating an instance(aka object) from markStruct. And you initialize that instance with 'mark1=98, mark2=96, mark3=100'.

'Self' is the reference to that instance itself. So, 'marks' instance contain variable mark1 mark2 & mark3 with their values respectively.

So, when you use print function, marks.mark1/2/3 get their values from 'marks' instance.
That code block is need if you are using instance and want to initialize it with some variable.

PS i don't use swift. I just answer with my poor assumption and understanding. But, i think general usage of programming may be same in swift ,too.

Answer 2

thank you so much. I understood what you mean, it was useful )))

Answer 3

chunmadim nima demoqchiligizzi

Answer 4

O'rganib qolganimni o'ylamaydi O'g'iloy)))