Introduction

• Access modifiers are the keywords used to set access levels (visibility) for classes, methods, variables and constructors.
• They help in implementing encapsulation and maintaining security in object-oriented programming.
• Java provides four types of access modifiers:
  1. public
  2. protected
  3. default (no modifier)
  4. private
• Why Use Access Modifiers?
  • To hide internal implementation details (data hiding).
  • To control access to class members from outside the class or package.
  • To follow the principles of encapsulation and object-oriented design.
  • To protect sensitive data and ensure modularity in large applications.

Types of Access Modifiers:-

1. public:
   • The member is accessible from anywhere in the program.
   • Can be used across packages and classes.
2. protected:
   • The member is accessible within the same package and also in subclasses (even if they are in different packages).
   • Cannot be accessed by non-subclass classes outside the package.
3. default (no modifier):
   • The member is accessible only within the same package.
   • Cannot be accessed from classes in different packages.
4. private:
   • The member is accessible only within the same class.
   • Cannot be accessed from outside the class, even by subclasses.

Access Control Table

Java Program Example:

• public class Car
  {
      private String model;
      protected int speed;
      public void startEngine()
      {
          System.out.println("Engine started");
      }
  }