What is Fileprivate in Swift?

fileprivate is one of the new Swift 3 access modifiers that replaces private in its meaning. fileprivate defines an entity (class, extension, property, ) as private to everybody outside the source file it is declared in, but accessible to all entities in that source file.Click to see full answer. Then, what is the difference between private and Fileprivate in Swift?internal allows use from any source file in the defining module but not from outside that module. fileprivate allows use only within the defining source file. private allows use only from the enclosing declaration and new in Swift 4, to any extensions of that declaration in the same source file.Additionally, what is difference between open and public in Swift? In short: An open class is accessible and subclassable outside of the defining module. An open class member is accessible and overridable outside of the defining module. A public class is accessible but not subclassable outside of the defining module. Keeping this in consideration, when should I use Fileprivate? You use fileprivate for things that are used inside of your extensions within the same file as your class/struct but outside of their defining curly braces (ie. their lexical scope). File-private access restricts the use of an entity to its own defining source file.What are access specifiers in Swift?As of Xcode 6 beta 4, Swift has access modifiers. From the release notes: Swift access control has three access levels: private entities can only be accessed from within the source file where they are defined. internal entities can be accessed anywhere within the target where they are defined.