Practice Class Definitions

Topics
  1. Basic Class Definitions & Testing
  2. Practice Exercises - Real World Scenarios

Basic Class Definitions & Testing

Here are five exercises for practicing basic class definitions and testing them in Tester class:

Exercise 1: Student Class

Scenario: Create a class to represent a student in a school system.

  • Class Name: Student
  • Fields:
    • String studentId – The student’s unique ID.
    • String name – The student’s full name.
    • double gpa – The student’s Grade Point Average.

Task:

  • Create a Student class with the above fields.
  • In a tester class, create an instance of Student, set the values for the fields, and print them out.

Exercise 2: Book Class

Scenario: Create a class to represent a book in a library.

  • Class Name: Book
  • Fields:
    • String isbn – The International Standard Book Number.
    • String title – The title of the book.
    • String author – The name of the author.

Task:

  • Create a Book class with the above fields.
  • In a tester class, create an instance of Book, assign values to the fields, and print the book details.

Exercise 3: Car Class

Scenario: Create a class to represent a car in a dealership system.

  • Class Name: Car
  • Fields:
    • String licensePlate – The car’s license plate number.
    • String make – The manufacturer of the car (e.g., Toyota, Ford).
    • String model – The model of the car (e.g., Camry, Mustang).

Task:

  • Create a Car class with the above fields.
  • In a tester class, create an instance of Car, set the field values, and print the car information.

Exercise 4: Movie Class

Scenario: Create a class to represent a movie in a streaming service.

  • Class Name: Movie
  • Fields:
    • String movieId – The unique ID of the movie.
    • String title – The title of the movie.
    • int durationMinutes – The duration of the movie in minutes.

Task:

  • Create a Movie class with the above fields.
  • In a tester class, create an instance of Movie, set the field values, and print out the movie details.

Exercise 5: Employee Class

Scenario: Create a class to represent an employee in a company.

  • Class Name: Employee
  • Fields:
    • String employeeId – The employee’s unique ID.
    • String name – The employee’s full name.
    • double salary – The employee’s salary.

Task:

  • Create an Employee class with the above fields.
  • In a tester class, create an instance of Employee, set the field values, and print out the employee’s information.

These exercises will help solidify your understanding of creating classes, defining fields, and directly accessing them in Java.

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Exercises on Applying Class Definitions to new Scenarios

Here are five different exercises with similar structure as Car example and challenges that you can observe and practice:

  1. Water Dispenser
    • Fields:
      • waterLevel (liters)
      • capacity (liters)
      • dispenseRate (liters per cup)
    • Methods:
      • addWater(amount) (liters)
      • dispenseWater(cups) (cups)
    • Conversion hint: If dispenseWater takes cups as input, you’ll need to convert cups to liters using the dispenseRate.
  2. Mobile Phone Battery
    • Fields:
      • batteryLevel (percentage)
      • maxBattery (percentage)
      • batteryConsumptionRate (percentage per hour)
    • Methods:
      • chargePhone(amount) (percentage)
      • usePhone(hours) (hours)
    • Conversion hint: No unit conversion is needed if everything is in percentages and hours, but ensure battery usage doesn’t exceed batteryLevel.
  3. Elevator
    • Fields:
      • currentFloor (floor number)
      • maxFloor (floor number)
      • minFloor (floor number)
      • capacity (kilograms)
      • currentLoad (kilograms)
    • Methods:
      • loadPassengers(count) (number of passengers)
      • moveToFloor(floor) (floor number)
    • Conversion hint: You may need to convert the number of passengers to weight (currentLoad) based on an average passenger weight.
  4. Coffee Machine
    • Fields:
      • waterLevel (milliliters)
      • coffeeBeans (grams)
      • maxCapacityWater (milliliters)
      • maxCapacityBeans (grams)
    • Methods:
      • addWater(amount) (milliliters)
      • addBeans(amount) (grams)
      • brewCoffee(cups) (cups)
    • Conversion hint: Convert the number of cups into milliliters of water and grams of beans based on the average water and beans per cup of coffee.
  5. Printer
    • Fields:
      • paperTrayLevel (sheets)
      • maxTrayCapacity (sheets)
      • tonerLevel (percentage)
      • paperConsumptionPerPage (sheets per page)
    • Methods:
      • addPaper(amount) (sheets)
      • printPages(pages) (pages)
    • Conversion hint: For printPages, ensure the number of pages translates correctly into the required sheets of paper, and check toner consumption for each page.

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Go back to Class Definitions to learn more with examples.

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