Java Reference
In-Depth Information
Display 7.9
Access Modii ers
package somePackage;
public class A
{
public int v1;
protected int v2;
int v3. //package
//access
private int v4;
public class B
{
can access v1.
can access v2.
can access v3.
cannot access v4.
In this diagram, “access” means access
directly, that is, access by name.
public class C
extends A
public class D
extends A
public class E
{
{
{
can access v1.
cannot access v2.
cannot access v3.
cannot access v4.
can access v1.
can access v2.
can access v3.
cannot access v4.
can access v1.
can access v2.
cannot access v3.
cannot access v4.
A line from one class to another means the lower class
is a derived class of the higher class.
If the instance variables are
replaced by methods, the same
access rules apply.
Package Access
If you do not place any of the modifiers public , private , or protected before an
instance variable or method definition, then the instance variable or method is said to have
package access . Package access is also known as default access and as friendly access .
If an instance variable or method has package access, it can be accessed by name inside
the definition of any class in the same package, but not outside of the package.
 
 
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