Practice Encapsulation

Topics

1. Implementing Encapsulation
2. Next Topic: Constructors

Implementing Encapsulation

Let’s update the classes from the previous exercises to incorporate encapsulation.

General Implementation Tips:

• Private Fields: Use the private keyword to make fields private, restricting direct access from outside the class.
• Getters and Setters: Write a getter method to retrieve each field’s value and a setter method to modify it.
• Validation: Consider adding validation in setter methods to ensure the data is valid (e.g., GPA should be between 0.0 and 10.0).

Exercise 1: Student Class

Scenario: Update the Student class to implement encapsulation.

• Original Fields:
  • String studentId
  • String name
  • double gpa

Instructions:

1. Update the Student class to make the fields private.
2. Add getter and setter methods for each field.
3. In the tester class, update the code to use the setters to assign values and the getters to retrieve and print the values.

Exercise 2: Book Class

Scenario: Update the Book class to implement encapsulation.

• Original Fields:
  • String isbn
  • String title
  • String author

Instructions:

1. Update the Book class to make the fields private.
2. Add getter and setter methods for each field.
3. In the tester class, update the code to use the setters to assign values and the getters to retrieve and print the book details.

Exercise 3: Car Class

Scenario: Update the Car class to implement encapsulation.

• Original Fields:
  • String licensePlate
  • String make
  • String model

Instructions:

1. Update the Car class to make the fields private.
2. Add getter and setter methods for each field.
3. In the tester class, update the code to use the setters to assign values and the getters to retrieve and print the car information.

Exercise 4: Movie Class

Scenario: Update the Movie class to implement encapsulation.

• Original Fields:
  • String movieId
  • String title
  • int durationMinutes

Instructions:

1. Update the Movie class to make the fields private.
2. Add getter and setter methods for each field.
3. In the tester class, update the code to use the setters to assign values and the getters to retrieve and print the movie details.

Exercise 5: Employee Class

Scenario: Update the Employee class to implement encapsulation.

• Original Fields:
  • String employeeId
  • String name
  • double salary

Instructions:

1. Update the Employee class to make the fields private.
2. Add getter and setter methods for each field.
3. In the tester class, update the code to use the setters to assign values and the getters to retrieve and print the employee’s information.

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Next Topic: Constructors

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