Object Oriented Programming Lab
Class Vs Abstract Class Vs Interface:
Class
class Animal {
void sound() {
A regular blueprint to create objects.
System.out.println("Animal sound");
Can have both properties and methods (with full implementation). }
Can use inheritance (one class can extend another). }
Abstract Class
A partially completed class.
Can have both implemented and unimplemented (abstract) methods.
Can't be instantiated directly.
Used as a base class in inheritance. abstract class Animal {
abstract void sound(); // no body
Interface void sleep() {
System.out.println("Sleeping...");
}
A completely abstract type }
Contains only method signatures (by default).
Used to define a contract for classes to follow.
A class implements an interface (can implement multiple interfaces).
interface Animal {
void sound(); // no body
Relationship with Inheritance: }
Summary:
Practice Questions for Midterm
1.
1. Define an interface `Product` with methods `String getProductName()` and `void produce()`. [2]
2. Create a class `CentralLocking` implementing the `Product` interface: [3]
- Add a private property `String productName`
- Implement the constructor to initialize `productName`.
- Define `getProductName()` to return the product name.
- Define `produce()` to print "Producing Central Locking System".
3. Create a class `GearLocking` implementing the `Product` interface: [3]
- Add a private property `String productName`
- Implement the constructor to initialize `productName`.
- Define `getProductName()` to return the product name.
- Define `produce()` to print "Producing Gear Locking System".
4. Create an abstract class `Car`: [3]
- Add two protected properties: `Product product` and `String carType`.
- Create a constructor to initialize `product` and `carType`.
- Define a method `printDetails()` to print car type and product name.
- Add two abstract methods: `void assemble()` and `void produceProduct()`.
5. Create a concrete class `BMW` extending `Car`: [3]
- Implement `assemble()` to print: "Assembling [Central Locking System] for [BMW X5 Model]". The []
parts must be printed by calling the method of suitable variable.
- Implement `produceProduct()` to call `produce()` on the product and print: "Modifying product [Gear
Locking System] according to [BMW X5 Model]".
6. Create a concrete class `Mercedes` extending `Car`: [3]
- Implement `assemble()` to print: "Assembling [Central Locking System] for [Mercedes GLS Model]". -
Implement `produceProduct()` to call `produce()` on the product and print: "Modifying product [Gear
Locking System] according to [Mercedes GLS Model]"
7. Create a `Main` class: [3]
- Instantiate `CentralLocking` and `GearLocking` objects.
- Create `BMW` and `Mercedes` objects using respective products.
- Call `produceProduct()` and `assemble()` methods on both car objects
2.
Write a Java program to manage a New Year To-Do List by following the instructions bellow:
A. Create an abstract class Task:
→ Variables: taskName (String) and deadline (String), Status (String); all the variables must be
protected.
→ A constructor to initialize these variables, but Status will have default value as “Incomplete”
→ An abstract method perform() that specifies the tasks operation.
→ An abstract method getDetails() that provides the tasks details.
→ A non-abstract method displayDeadline() that prints task deadline only.
Example: “Task Deadline Month Name.”
→ Another non-abstract method displayStatus() that prints the tasks status
complete/incomplete with task name.
→ Example: “Learning OOP is Incomplete.”
B. Create concrete subclasses PersonalTask and ProfessionalTask that inherit from Task.
→ Class PersonalTask: Print a message about completing the task and include details like
taskName and deadline.
→ Class ProfessionalTask: Similar to PersonalTask, but emphasize its professional context.
→ Both class will override displayDeadline(), displayStatus() to format the deadline differently
for each type of task. DisplayDeadline(): “Skill development deadline August.” And
displayStatus(): “Skill development is incomplete.”
→ Both class will have a common method TaskComplete(), calling this method will change the
status of the corresponding task from incomplete to completed.
C. In the TestClass:
→ Create 2 object of PersonalTask and 2 objects of ProfessionalTask, initializing them with
appropriate values.
Example:
Personal Task : Losing 5kg, Ocotber.
Professional Task: Being pro in programming, December
→ Call all the methods using the objects created.
→ At the end update all the task to complete state and call displayStatus() to check the task
update.
3.
Implementation Details:
● Use an interface named Individual which contains the methods printDetails() and calculate(). 4
● Create an abstract class named Person which implements the Individual interface, has the
common properties name and age and has Constructors to initialize them. 4
● Create concrete classes Doctor and Patient that extend the Person abstract class,
implementing the additional methods and properties. 4
● Create another class named HospitalManagement that contains the main method. 1
● Take input from the user the details of the following three different doctors and initialize the
objects using constructors. 2
○ name="Dr. Smith", age=35, specialization="Cardiology", yearsExperience=8,
patientsTreated=600, visitAmount=1200, outdoorHours=20
○ name="Dr. Johnson", age=38, specialization="Neurology", yearsExperience=10,
patientsTreated=820, visitAmount=1400, outdoorHours=18
○ name="Dr. Green", age=42, specialization="Gynecology", yearsExperience=15,
patientsTreated=1300, visitAmount=1500, outdoorHours=20
● Take input from the user the details of four different patients and initialize the objects using
constructors. 2
○ name="Alice Wilstone", age=20, disease="Flu", visitAmount=400, testAmount=1000,
wasAdmitted=false
○ name="Bob Nielsen", age=35, disease="Diabetes", visitAmount=1200,
testAmount=8000, wasAdmitted=true
○ name="Jake Peralta", age=56, disease="Heart disease", visitAmount=2000,
testAmount=1200, wasAdmitted=true
○ name="Emma Stone", age=45, disease="Cancer", visitAmount=500,
testAmount=1500, wasAdmitted=true
● Calculate the amount of bonus Dr. Johnson should receive by invoking the appropriate 1
methods.
● Mr. Nielsen has visited the hospital and paid 2000 taka as doctors visit and spent 10000 taka for
the test. Update his total bill invoking appropriate methods. 1
● Calculate the percentage of discount Mr. Nielsen should receive by invoking the appropriate
Method. 1
