Classes, objects, interfaces, constructors, and functions, as well as properties and their setters, can have visibility modifiers. Getters always have the same visibility as their properties.
There are four visibility modifiers in Kotlin:
public. The default visibility is
On this page, you'll learn how the modifiers apply to different types of declaring scopes.
Functions, properties, classes, objects, and interfaces can be declared at the "top-level" directly inside a package:
If you don't use a visibility modifier,
publicis used by default, which means that your declarations will be visible everywhere.
If you mark a declaration as
private, it will only be visible inside the file that contains the declaration.
If you mark it as
internal, it will be visible everywhere in the same module.
protectedmodifier is not available for top-level declarations.
For members declared inside a class:
privatemeans that the member is visible inside this class only (including all its members).
protectedmeans that the member has the same visibility as one marked as
private, but that it is also visible in subclasses.
internalmeans that any client inside this module who sees the declaring class sees its
publicmeans that any client who sees the declaring class sees its
If you override a
protected or an
internal member and do not specify the visibility explicitly, the overriding member will also have the same visibility as the original.
Use the following syntax to specify the visibility of the primary constructor of a class:
Here the constructor is private. By default, all constructors are
public, which effectively amounts to them being visible everywhere the class is visible (this means that a constructor of an
internal class is only visible within the same module).
Local variables, functions, and classes can't have visibility modifiers.
internal visibility modifier means that the member is visible within the same module. More specifically, a module is a set of Kotlin files compiled together, for example:
An IntelliJ IDEA module.
A Maven project.
A Gradle source set (with the exception that the
testsource set can access the internal declarations of
A set of files compiled with one invocation of the