Access modifiers in java

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1. DEFINATION : ACCESS SPECIFIERS Access specifiers(or access modifiers) are keywords in object-oriented languages that sets the accessibility of the classes , methods and others members

2. . THERE ARE 4 TYPES OF JAVA ACCESS SPECIFIERS: DEFAULT PRIVATE PROTE C TED iv. PUBLIC

3. Access Modifiers in java • Java provides a number of access modifiers to set access levels for classes, variables, methods and constructors. The four access levels are − • Visible to the package , the default . No modifiers are needed. • Visible to the class only ( private ). • Visible to the world ( public ). • Visible to the package and all subclasses ( protected ).

4. 1 . ]DEFAULT ACCESS SPECIFIER: No keyword is required to specify default access specifier When no access modifier is specified for a class, method or data member it is said to be having the default access specifier by default. Default access specifier are accessible within the same package.

5. 2 . ]PRIVATE ACCESS SPECIFIER: The private access specifier is specified using the keyword private. The methods or data members declared as private are accessible only within the class in which they are declared. Any other class of same package will not be able to access these members. Classes or interface can not be declared as private.

6. PRIVATE E xample class  A{   private   int  data= 40 ;   private   void   msg (){System.out.println( "Hello java" );}   }      public   class  Simple{     public   static   void  main(String args[]){      A  obj = new  A();       System.out.println ( obj.data ); //Compile Time Error       obj.msg(); //Compile Time Error       }   }  

7. PRIVATE E xample – setter & getter public class Logger { private String format; public String getFormat () { return this.format ; } public void setFormat (String format) { this.format = format; } }

8. PRIVATE E xample – setter & getter class Data { private String name; // getter method public String getName () { return this.name; } // setter method public void setName (String name) { this.name= name; } } public class Main { public static void main(String[] main){ Data d = new Data(); // access the private variable using the getter and setter d.setName (“ Ganpat Univ "); System.out.println ( d.getName ()); } }

9. 3 . ]PROTECTED ACCESS SPECIFIER: The protected access specifier is specified using the keyword protected . The methods or data members declared as protected are accessible within same package or sub classes in different package.

10. PR OTECTED E xample class Animal { // protected method protected void display() { System.out.println("I am an animal"); } } class Dog extends Animal { public static void main(String[] args) { // create an object of Dog class Dog d = new Dog(); // access protected method d.display (); } }

11. PR OTECTED E xample package p1; //Class A public class A { protected void display() { System.out.println("Learning JAVA"); } } package p2; import p1.*; //importing all classes in package p1 //Class B is subclass of A class B extends A { public static void main(String args[]) { B obj = new B(); obj.display (); } }

12. . 4]PUBLIC ACCESS SPECIFIER: The public access specifier is specified using the keyword public . The public access specifier has the widest scope among all other access modifiers. Classes, methods or data members which are declared as public are accessible from every where in the program. There is no restriction on the scope of a public data members.

13. ACCESS LEVELS Specifier Class Package Subclass Everywhere Default Y Y N N Private Y N N N Protected Y Y Y N Public Y Y Y Y

14. Access Modifiers