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Java Access Modifiers – public, protected, private and default

Java Access Modifiers – public, protected, private and default

The access to classes, constructors, methods and fields are regulated using access modifiers i.e. a class can control what information or data can be accessible by other classes. To take advantage of encapsulation, you should minimize access whenever possible.
A Class can only be default of public
If a class does not have any access modifier before it, it means it has default access i.e.
it can be accessed only from other classes in the same package.
If a modifier for class is public it means it can be accessed anywhere.  But we can have only public class in a single source file and the name of the file should be same as public class name.

There are 4 types of java access modifiers:
  1. private
  2. protected
  3. default
  4. public
Private : Fields, methods or constructors declared private are strictly controlled, which means they cannot be accesses by anywhere outside the enclosing class.

The private (most restrictive) fields or methods cannot be used for classes and Interfaces. It also cannot be used for fields and methods within an interface.  A standard design strategy is to make all fields private and provide public getter methods for them.

Protected:  If class member is “protected” then it will be accessible only to the classes in the same package and to the subclasses.
This modifier is less restricted from private but more restricted from public access. Usually we use this keyword to make sure the class variables are accessible only to the subclasses.

Default : If you don't use any modifier, it is treated as default by default. The default modifier is accessible only within package.
This access is more restricted than public and protected but less restricted than private.

Public: Fields, methods and constructors declared public (least restrictive) within a public class are visible to any class in the Java program, whether these classes are in the same package or in another package.


Order as per their accessibility : public(Fully Accessible) > protected  >default > private (least accessible)




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