Chapter 4.0: Access modifier in Java-Access Modifiers for Class,Access Modifiers for Variable (Instance / Static Variable), Access Modifiers for Methods,

Access modifier decides how other part of the java world can access given code(If Possible)
In total there are 3 access modifiers available. But 4 access control. 4th access control will be given when you don’t specify any access modifier which is Default.

Access Control:

• Public
• Private
• Protected
• Default

Access modifiers(Some or All) can be applied on Class, Variable, Methods.

Access Modifiers for Class

Class can use only two of the Access Modifier.

Public

Public means given class will be accessible from all the classes available in Java world.

Default

Default means it will be accessible only from the classes inside package in which it is defined.

Java Access Modifiers Table for Class

Visibility	Public Access Modifier	Default Access Modifier
Within Same Package	Yes	Yes
From Outside the Same Package	Yes	No

Access Modifiers for Variable (Instance / Static Variable)

Variables are eligible for all 4 level of Modifier.

• Default
• Public
• Protected
• Private

Note*: Before checking the visibility of variable check the visibility of class first. If class is visible only then variables visibility make any difference. If class is not visible then no variable(Not even public) will be accessible.

Default

Variable with Default access will be accessible only from the classes inside package in which it is defined. Any method in any class which is defined in same package can access given variable in any way.(Via Inheritance or Direct access)

Public

Public means given variable will be accessible from all the class available in Java world. Any method in any class can access given variable in any way.(Via Inheritance or Direct access)

Protected

Protected means it will be accessible only from the sub classes(Inside / Outside package) (Via Inheritance Only).
Protected respect class subclass relation while Default doesn’t. This is the only difference between these 2 modifier(Protected & Default).

Private

Private means it will be accessible only from within class. No one can access the given variable from outside class(Not even subclass).

Java Access Modifiers Table for Variable

Visibility	Public Access Modifier	Private Access Modifier	Protected Access Modifier	Default Access Modifier
Within Same Class	Yes	Yes	Yes	Yes
From Any Class in Same Package	Yes	No	Yes	Yes
From Any Sub Class in Same Package	Yes	No	Yes	Yes
From Any Sub Class from Different Package	Yes	No	Yes(Only By Inheritance)	No
From Any Non Sub Class in Different Package	Yes	No	No	No

Access Modifiers for Methods

Default

Default means it will be accessible only from the classes inside package in which it is defined. Any method in any class which is defined in same package can access given method in any way.(Via Inheritance or Direct access)

Public

Public means given method will be accessible from all the class method in Java world. Any method in any class can access given method in any way.(Via Inheritance or Direct access) depending on class level access.

Protected

Protected means it will be accessible only from the sub classes(Inside / Outside package) .
Note* Protected respect class subclass relation while Default doesn’t. This is the only difference between these 2 (Default & Protected)modifier.

Private

Private means it will be accessible only from within class. No one can access the given method from outside class(Not even subclass).

Java Access Modifiers Table for Method

Visibility	Public Access Modifier	Private Access Modifier	Protected Access Modifier	Default Access Modifier
Within Same Class	Yes	Yes	Yes	Yes
From Any Class in Same Package	Yes	No	Yes	Yes
From Any Sub Class in Same Package	Yes	No	Yes	Yes
From Any Sub Class from Different Package	Yes	No	Yes(Only By Inheritance)	No
From Any Non Sub Class in Different Package	Yes	No	No	No