README.md

Module 3: Abstraction & Encapsulation

Objective

The objective of this module is to get hands-on experience with the following topics:

1. Introduction to Abstraction
2. Abstract classes and interfaces
3. Access Modifiers (public, private, protected)

Lab 3.1

Objectives

1. Understand and implement abstraction in Java.

Problem Statement

Create an interface Payroll and implement the following abstract methods in a PayrollImpl class.

1. void displayProfile(Employee employee);
2. float calculateNetSalary(Employee employee);
3. float calculateNetSalaryAfterIncrement(Employee employee);
4. void displayProfile(int empId);
5. void displayProfile(float fromSalaryRange, float toSalaryRange);
6. void displayProfile(String department);

Tasks

1. Create an interface named Payroll with the following methods:

   • void displayProfile(Employee employee);
   • float calculateNetSalary(Employee employee);
   • float calculateNetSalaryAfterIncrement(Employee employee);
   • void displayProfile(int empId);
   • void displayProfile(float fromSalaryRange, float toSalaryRange);
   • void displayProfile(String department);

2. Implement the PayrollImpl class that implements the Payroll interface.

3. Override all the methods with the @Override annotation.

   Method Instructions:

   • displayProfile(Employee employee)

     • Action: Call employee.displayProfile().

   • calculateNetSalary(Employee employee)

     • Action: Call and return employee.calculateNetSalary().

   • calculateNetSalaryAfterIncrement(Employee employee)

     • Action: Call and return employee.calculateNetSalaryAfterIncrement().

   • displayProfile(int empId)

     • Action: Print a message to indicate displaying the profile for the given Employee ID.
     • Example: System.out.println("This method display the employee profile with Employee ID ");

   • displayProfile(float fromSalaryRange, float toSalaryRange)

     • Action: Print a message to indicate displaying profiles within the given salary range.
     • Example: System.out.println("This method display all employee profiles from and to given salary ranges");

   • displayProfile(String department)

     • Action: Print a message to indicate displaying profiles for the given department.
     • Example: System.out.println("This method display all the employee profiles from a given department");

4. In the Main class, create the PayrollImpl object and invoke all the methods by passing the Developer and Designer objects as implemented in the previous lab.