jrasmusson/ios-professional-course

Course for iOS Professionals

ios-professional-course's Issues

Struct can be stored on the heap

• https://github.com/jrasmusson/ios-professional-course/blob/main/Knowing/StackVsHeap/README.md

Thank you for useful explanation of reference, value type in swift!!🥳

I created issue because I think some contents need to be added.

When ReferenceType owned ValueType, ValueType is stored on the heap

The following is an example code.

import Foundation

struct ValueType {
    var member1: Int
    var member2: Int
}

class ReferenceType {
    var member1: Int
    var member2: Int
    var value: ValueType
    
    init(member1: Int, member2: Int) {
        self.member1 = member1
        self.member2 = member2
        self.value = ValueType(member1: member1 + 1, member2: member2 + 1)
    }
}

func test() {
    var ref1 = ReferenceType(member1: 9, member2: 3)

    withUnsafePointer(to: &ref1) {
        print("ref1 address: \($0)")
    }
    
    withUnsafePointer(to: &ref1.value) {
        print("ref1.value address: \($0)")
    }
}

test()

If you check the memory area you can see that the ValueType is stored on the heap

thank you for reading it!

Aaa