Welcome to the article on “Practice Problems on Inheritance in Java”. Inheritance is a powerful concept in object-oriented programming, and it is important to understand its various aspects and applications. If you want to learn more about inheritance, please refer to our previous article titled “Inheritance in Java“. Additionally, if you are interested in learning about the different types of inheritance in Java, please refer to our article on “Types of Inheritance in Java“. In this article, we will cover a range of practice problems on inheritance in Java, which will help you solidify your understanding and skills in this area.
Practice Problem on Single Inheritance
| Create a class “Vehicle” with a method “start()” that prints “Vehicle started”. Create a subclass “Car” that extends “Vehicle” and overrides the “start()” method to print “Car started”. Create an object of the “Vehicle” class and call the “start()” method. Create an object of the “Car” class and call the “start()” method. |
| Solution : Click here to view answer. |
| Create a class “Person” with fields “name” and “age” and a method “display()” that prints the name and age of the person. Create a subclass “Employee” that extends “Person” and adds a field “salary” and a method “display()” that prints the name, age, and salary of the employee. Create an object of the “Person” class and call the “display()” method. Create an object of the `Employee` class and call the “display()” method. |
| Solution : Click here to view answer. |
| Create a class “Shape” with a method “getArea()” that returns the area of the shape. Create a subclass “Rectangle” that extends “Shape” and adds fields “length” and “width” and overrides the “getArea()” method to return the area of the rectangle. Create an object of the “Shape” class and call the “getArea()” method. Create an object of the “Rectangle” class and call the “getArea()” method. |
| Solution : Click here to view answer. |
| Create a class “Animal” with a method “makeSound()” that prints a sound. Create a subclass “Dog” that extends “Animal” and overrides the “makeSound()” method to print “Woof!”. Create an object of the “Animal” class and call the “makeSound()” method. Create an object of the “Dog” class and call the “makeSound()” method. |
| Solution : Click here to view answer. |
| Create a class “BankAccount” with fields “accountNumber”, “balance”, and “interestRate” and a method “deposit()” that adds an amount to the balance. Create a subclass “SavingsAccount” that extends “BankAccount” and adds a field “minimumBalance” and a method “withdraw()” that subtracts an amount from the balance. Create an object of the “BankAccount” class and call the “deposit()” method. Create an object of the “SavingsAccount” class and call the “deposit()” and “withdraw()” methods. |
| Solution : Click here to view answer. |
Practice Problem on Multilevel Inheritance
| Create a class “Person” with fields “name” and “age” and a method “display()” that prints the name and age of the person. Create a subclass “Employee” that extends “Person” and adds a field “salary” and a method “display()” that prints the name, age, and salary of the employee. Create a subclass “Manager” that extends “Employee” and adds a field “department” and a method “display()” that prints the name, age, salary, and department of the manager. Create an object of the “Person” class and call the “display()” method. Create an object of the “Employee” class and call the “display()” method. Create an object of the “Manager” class and call the “display()” method. |
| Solution : Click here to view answer. |
| Create a class “Animal” with a method “makeSound()” that prints a sound. Create a subclass “Mammal” that extends “Animal” and adds a method “giveBirth()” that prints “Giving birth”. Create a subclass “Dog” that extends “Mammal” and overrides the “makeSound()” method to print “Woof!”. Create an object of the “Animal” class and call the “makeSound()” method. Create an object of the “Mammal” class and call the “makeSound()” and “giveBirth()” methods. Create an object of the “Dog” class and call the “makeSound()” and “giveBirth()” methods. |
| Solution : Click here to view answer. |
| Create a class “Vehicle” with a method “start()” that prints “Vehicle started”. Create a subclass “Car” that extends “Vehicle” and adds a method “drive()” that prints “Car driving”. Create a subclass “SportsCar” that extends “Car” and overrides the “drive()” method to print “Sports car driving fast”. Create an object of the “Vehicle” class and call the “start()” method. Create an object of the “Car” class and call the “start()” and “drive()” methods. Create an object of the “SportsCar” class and call the “start()” and “drive()” methods. |
| Solution : Click here to view answer. |
| Create a class “Shape” with a method “getArea()” that returns the area of the shape. Create a subclass “Rectangle” that extends “Shape” and adds fields “length” and “width” and overrides the “getArea()” method to return the area of the rectangle. Create a subclass “Box” that extends “Rectangle” and adds a field “height” and overrides the “getArea()” method to return the surface area of the box. Create an object of the “Shape” class and call the “getArea()” method. Create an object of the “Rectangle” class and call the “getArea()” method. Create an object of the “Box” class and call the “getArea()” method. |
| Solution : Click here to view answer. |
| Create a class “BankAccount” with fields “accountNumber”, “balance”, and “interestRate” and a method “deposit()” that adds an amount to the balance. Create a subclass “SavingsAccount” that extends “BankAccount” and adds a field “minimumBalance” and a method “withdraw()” that subtracts an amount from the balance. Create a subclass “FixedDepositAccount” that extends “SavingsAccount” and adds a field “term” and a method “getInterest()” that returns the interest earned on the account. Create an object of the “BankAccount” class and call the “deposit()” method. Create an object of the “SavingsAccount” class and call the “deposit()” and “withdraw()” methods. Create an object of the “FixedDepositAccount” class and call the “deposit()” |
| Solution : Click here to view answer. |
Practice Problem on Hierarchical Inheritance
| Create a class “Shape” with a method “calculateArea()” that calculates and returns the area of the shape. Create two subclasses “Rectangle” and “Triangle” that extend “Shape” and implement the “calculateArea()” method. |
| Solution : Click here to view answer. |
| Create a class “Vehicle” with a method “drive()” that displays a message “Driving a vehicle”. Create two subclasses “Car” and “Bike” that extend “Vehicle” and implement the “drive()” method to display “Driving a car” and “Driving a bike” respectively. |
| Solution : Click here to view answer. |
| Create a class “Animal” with a method “move()” that displays a message “The animal is moving”. Create two subclasses “Bird” and “Fish” that extend “Animal” and implement the “move()” method to display “The bird is flying” and “The fish is swimming” respectively. |
| Solution : Click here to view answer. |
| Create a class “BankAccount” with a method “deposit()” that adds money to the account. Create two subclasses “SavingsAccount” and “CheckingAccount” that extend “BankAccount” and implement the “deposit()” method to add interest to the account balance for savings account and display a message for checking account. |
| Solution : Click here to view answer. |
| Create a class “Person” with a method “speak()” that displays a message “The person is speaking”. Create two subclasses “Student” and “Teacher” that extend “Person” and implement the “speak()” method to display “The student is asking a question” and “The teacher is giving a lecture” respectively. |
| Solution : Click here to view answer. |
In conclusion, this article presented several practical problems on inheritance in Java, covering various concepts such as single inheritance, hierarchical inheritance, and more. By practicing these problems, you can improve your understanding of inheritance and become better at writing efficient and effective code using inheritance. We hope that these problems will be useful for you in your programming journey. If you want to learn more about inheritance or related concepts, refer to our previous articles such as “Inheritance in Java” or “Types of Inheritance in Java“
