swift - Private var is accessible from outside the class

Question

This was done in Playground, just to simplify.

class MyPrivateVar
{
    private var priv: String?
}

var myInstance = MyPrivateVar()

myInstance.priv = "Something"

No compiler warning. In fact auto-complete is showing priv without a problem. My understanding is that outside the boundaries of {} of the class, I'm not supposed to be able to see a private anything, func nor var.

Am I missing something?

Answer 1

Access modifiers in Swift are implemented differently than other languages. There are three levels:

private: accessible only within that particular file

internal: accessible only within the module (project)

public: accessible from anywhere

Unless marked otherwise, everything you write is internal by default.

The Swift blog had a post about access control when the features were introduced in beta 4, and Apple's documentation has a chapter as well.