Inheritance and Polymorphism

Objective

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

1. Overview of Inheritance
2. Working with Inheritance
3. Introduction to Polymorphism
4. Method Overloading and Method Overriding

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Problem Statement 1: Understanding and Implementing Inheritance

Objectives

1. Understand and Implement Inheritance in Java.
2. Invoking superclass argument constructors.

Problem Statement

Create subclasses of the Employee class and add the necessary properties and constructors by invoking the superclass constructors.

Tasks

1. Create Subclass Developer:

   • Extend from Employee class with a property noOfProjects.
   • Create both no-arg and argument constructors, invoking the superclass constructors.

2. Create Subclass Designer:

   • Extend from Employee class with a property noOfWebsites.
   • Create both no-arg and argument constructors, invoking the superclass constructors.

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Problem Statement 2: Understanding and Implementing Method Overriding and Polymorphism

Objectives

1. Understand and implement method overriding.
2. Implement runtime polymorphism.

Problem Statement

Override calculateNetSalary() and calculateNetSalaryAfterIncrement() methods in the Employee class and in Developer and Designer classes respectively.

Tasks

1. Implement Methods in Employee Class:

   • float calculateNetSalary(): Calculate the Net Salary after tax deduction.

    float calculateNetSalary() {
       return grossSalary - federalTax - stateTax;
    }  
   

   • float calculateNetSalaryAfterIncrement(): Calculate the incremented Net Salary after the increment.

    float calculateNetSalaryAfterIncrement() {
      float netSalary;
      netSalary = calculateNetSalary();
      netSalary += (netSalary * incrementPercentage / 100);
      return netSalary;
    } 
   

2. Update displayProfile() Method in Employee Class:

   • Display the Net Salary and Net Salary after the increment.

3. Override Methods in Developer and Designer Classes:

   • Override calculateNetSalary(), calculateNetSalaryAfterIncrement(), and displayProfile() methods with the appropriate logic.

4. Create Payroll Class:

   • Implement float calculateNetSalary(Employee employee) to return the calculateNetSalary() method of the Employee class.
   • Implement float calculateNetSalaryAfterIncrement(Employee employee) to return the calculateNetSalaryAfterIncrement() method of the Employee class.

5. Main Class Implementation:

   • Create two Developer objects with necessary values.
   • Create two Designer objects with necessary values.
   • Create a Payroll object and invoke calculateNetSalary() and calculateNetSalaryAfterIncrement() methods for Developer and Designer objects.
   • Include SOP messages inside Developer and Designer class methods to observe which methods are invoked.

Problem Statement 3: Understanding and Creating Overloaded Methods

Objectives

1. Understand and create overloaded methods.

Problem Statement

Create overloaded methods for the displayProfile() method of the Payroll class with different input parameters.

Tasks

1. Create Overloaded Methods in Payroll Class:
   • void displayProfile(int empId): Implement with an SOP statement to indicate method invocation.
   • void displayProfile(float fromSalaryRange, float toSalaryRange): Implement with an SOP statement to indicate method invocation.
   • void displayProfile(String department): Implement with an SOP statement to indicate method invocation.

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This README provides an overview of the exercises focusing on inheritance, polymorphism, and method overloading/overriding in Java. Follow the tasks to implement the required functionality and observe the expected outputs.