Assignment 3

Assignment 3  

Encapsulation TOPIC Questions

1.Write a Java program that encapsulates the Employee class with the following private attributes:

id (integer)

name (String)

salary (double)

Provide getter and setter methods for each attribute. Include the following constraints:

The id must be positive.

The salary must be greater than 3000. If not, set it to a default value of 3000.

Write a TestEmployee class to:

Create an Employee object.

Set the values for the attributes using setter methods.

Display the values using getter methods.

2. Bank Account Management

Problem:

Create a BankAccount class with the following private attributes:

accountNumber (String)

accountHolderName (String)

balance (double)

Implement:

Getter and setter methods for each attribute.

Validation:The accountNumber must be a 10-digit number.

The balance cannot be negative.

A method deposit(double amount) to add money to the account. Ensure the amount is positive.

A method withdraw(double amount) to deduct money from the account. Ensure the balance is sufficient.

Hint:Use String.length() to validate the account number.

3. Product Management System

Problem: Create a Product class to represent a product in a store. The class should have the following private attributes:

productId (int)

productName (String)

price (double)

quantity (int)

Implement:Getter and setter methods for each attribute.

Validation:The price must be greater than 0.

The quantity cannot be negative.

A method calculateTotalCost() to return the total cost as price * quantity.

Test Class:

Create a product object.

Set attributes using setter methods.

Display product details using getter methods.

Print the total cost of the product.

4. Library Book System

Problem:Design a Book class with these attributes:

bookId (String)

title (String)

author (String)

price (double)

Implement:Getter and setter methods with validation:

The bookId must start with "B" followed by digits (e.g., "B123").

The price must be positive.

Add a method displayBookDetails() to print all the details of a book.

5. Student Grade Management

Problem:Create a Student class with private attributes:

rollNumber (int)

name (String)

marks (array of doubles)

Implement: Getter and setter methods for the attributes.

A method calculateAverage() to return the average marks.

A method findGrade() that assigns a grade based on the average:

A: Average >= 90

B: 80 <= Average < 90

C: 70 <= Average < 80

F: Average < 70

Test Class:

Create a student object.

Set marks using a setter method.

Display the average and grade.

6. Car Rental System

Problem: Design a Car class with the following private attributes:

carId (String)

carName (String)

rentalPricePerDay (double)

Implement: 

Getter and setter methods with validation:

The rentalPricePerDay must be a positive value.

A method calculateRentalCost(int days) that calculates the total rental cost for a given number of days.

Test Class:

Create a Car object.

Input rental price and number of days.

Display the total rental cost.

Inheritance TOPIC Questions

1. Animal Hierarchy

Problem:Create a base class Animal with the following attributes and methods:

name (String)

age (int)

A method speak() that prints a generic message like "This is an animal."

Create subclasses:

Dog: Override the speak() method to print "The dog barks."

Cat: Override the speak() method to print "The cat meows."

Test Class:

Create objects of Animal, Dog, and Cat.

Call the speak() method on each object.

2. Employee-Manager Hierarchy

Problem:  Create a base class Employee with the following attributes and methods:

name (String) 

salary (double)

A method displayDetails() to print the employee's name and salary.

Create a subclass Manager: 

Add an additional attribute bonus (double).

Override the displayDetails() method to include the bonus.

Test Class:

Create objects of Employee and Manager.

Call displayDetails() for both objects.

3. Shape Hierarchy

Problem: Create a base class Shape with: 

A method calculateArea() that prints "Area calculation not defined."

Create subclasses: 

Circle:

Add an attribute radius (double).

Override calculateArea() to calculate the area of a circle: 

𝜋 × radius 2

π×radius 2

 Rectangle:

Add attributes length and breadth (double).

Override calculateArea() to calculate the area of a rectangle: 

length  × breadth

length×breadth.

Test Class:

Create objects of Shape, Circle, and Rectangle.

Call the calculateArea() method on each.

4. Vehicle Hierarchy

Problem: Create a base class Vehicle with: 

brand (String)

model (String)

A method displayInfo() to print the brand and model.

Create subclasses: 

Car: Add an attribute numberOfDoors (int). Override displayInfo() to include the number of doors.

Bike: Add an attribute type (String, e.g., "Sports" or "Cruiser"). Override displayInfo() to include the bike type.

Test Class:

Create objects of Vehicle, Car, and Bike.

Call displayInfo() for each object.

5. University System

Problem: Create a base class Person with:

name (String)

age (int)

A method showDetails() to print the name and age.

Create subclasses:  Student:

Add an attribute course (String).

Override showDetails() to include the course.

Professor: 

Add an attribute department (String).

Override showDetails() to include the department.

Test Class:

Create objects of Person, Student, and Professor.

Call showDetails() for each.

6. Bank Account Inheritance

Problem: Create a base class BankAccount with:

accountNumber (String)

balance (double)

Methods deposit(double amount) and withdraw(double amount).

Create subclasses:

SavingsAccount: Add an attribute interestRate (double). Add a method calculateInterest() that calculates interest based on the balance.

CheckingAccount: Add an attribute overdraftLimit (double). Override withdraw() to allow overdrafts up to the limit.

Test Class:

Create objects of SavingsAccount and CheckingAccount.

Test deposits, withdrawals, and interest calculation.

7. Appliance Inheritance

Problem: Create a base class Appliance with:

brand (String)

power (int, in watts)

A method showDetails() to print the brand and power.

Create subclasses:

WashingMachine: Add an attribute capacity (double, in kg). Override showDetails() to include the capacity.

Refrigerator: Add an attribute volume (double, in liters). Override showDetails() to include the volume.

Test Class:

Create objects of Appliance, WashingMachine, and Refrigerator.

Call showDetails() for each.

8. Payment System

Problem: Create a base class Payment with:

amount (double)

A method makePayment() to print "Payment of [amount] made."

Create subclasses: 

CreditCardPayment: Add an attribute cardNumber (String). Override makePayment() to include the card number.

CashPayment: Add an attribute cashGiven (double). Override makePayment() to include the cash given.

Test Class:

Create objects of Payment, CreditCardPayment, and CashPayment.

Call makePayment() for each.