Access levels for Java classes

Package-private

This describes the access level of the Java class in the official guidance:

At the top level-public, or package-private (no explicit modifier).

At the member Level-public, private, protected, or package-private (no explicit modifier).

Do not know what package-private is, so continue to look down, see such a passage:

A class may being declared with the modifier public, in which case, which is visible to all classes everywhere. If A class has no modifier (the default, also known as Package-private), it's visible only within its own package (Packag ES is named groups of related Classes-you would learn about them in a later lesson.)

Presumably, when a class does not have any access modifiers, his default access level is Package-private, which means that the other classes within the package are visible, and the classes outside the package are invisible, which is what we often call the packages level.

Access levels

Modifier	Class	Package	Subclass	World
Public	Y	Y	Y	Y
Protected	Y	Y	Y	N
No modifier	Y	Y	N	N
Private	Y	N	N	N

Access levels for Java classes