Is the class open public or private?

The access specifier open in Swift applies only to classes and class members (methods, properties). A class with the open modifier is the most accessible level. It is public.

The key difference between open and public in the context of classes:

Modifier	Accessibility within the module	Accessibility outside the module	Ability to inherit outside the module	Ability to override members outside the module
public	Yes	Yes	No	No
open	Yes	Yes	Yes	Yes

Thus, an open class is accessible from anywhere within the current module and from other modules, and can be inherited, with its members overridden in other modules.

// Example of a class with the open modifier
open class OpenClass {

    // Example of a member with the open modifier
    open func openMethod() {
        // Method implementation
    }

    // Example of a member with the public modifier
    public var publicProperty: Int = 0

    // Example of a member with the internal modifier
    internal var internalProperty: String = ""

    // Example of a member with the fileprivate modifier
    private var privateFileProperty: Double = 0.0

    // Example of a member with the private modifier
    private var privateProperty: Bool = false
}