ExamAdept

How can encapsulation be enforced in Python to make a variable 'employee_id' accessible only within its own class?

class Employee:
    def __init__(self, employee_id, __salary):
        self.employee_id = employee_id
        self.__salary = __salary

A:

Use a getter method for 'employee_id'

B:

Add a single underscore prefix before 'employee_id'

C:

Make 'employee_id' a global variable

D:

Add a double underscore prefix before 'employee_id'

Answer: D

Adding a double underscore prefix before 'employee_id' makes it a private variable, enforcing encapsulation within the class.

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In Python, what is the benefit of using a private variable with a double underscore prefix, such as __weight?

class Product:
    __weight = 0

    def update_weight(self, weight):
        Product.__weight += weight

A:

It improves code maintainability by hiding implementation details

B:

It allows unrestricted access to __weight

C:

It exposes all internal details of __weight

D:

It creates a global variable

Answer: A

Encapsulation with a double underscore prefix improves code maintainability by hiding the implementation details of the class attribute __weight.

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Consider the following Python code:

class Circle:
    def __init__(self, __radius):
        self.__radius = __radius

    def calculate_area(self):
        return 3.14 * (self.__radius ** 2)

What is the purpose of the calculate_area() method?

A:

To retrieve the area of the circle

B:

To set a new area for the circle

C:

To calculate the area of the circle

D:

To expose all internal details of the class

Answer: C

The calculate_area() method calculates and returns the area of the circle, demonstrating encapsulation.

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How can encapsulation be enforced in Python to make a variable 'serial_number' accessible only within its own class?

class ElectronicDevice:
    def __init__(self, serial_number, __brand):
        self.serial_number = serial_number
        self.__brand = __brand

A:

Use a getter method for 'serial_number'

B:

Add a single underscore prefix before 'serial_number'

C:

Make 'serial_number' a global variable

D:

Add a double underscore prefix before 'serial_number'

Answer: D

Adding a double underscore prefix before 'serial_number' makes it a private variable, enforcing encapsulation within the class.

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What is the primary purpose of the following Python class?

class Book:
    def __init__(self, title, __author):
        self.title = title
        self.__author = __author

    def get_author(self):
        return self.__author

A:

To create a new instance of the class

B:

To provide controlled access to the 'author' variable

C:

To define a public variable 'author'

D:

To allow unrestricted access to the 'author' variable

Answer: B

The get_author() method provides controlled and read-only access to the private variable '__author', demonstrating encapsulation.

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Questions for: Encapsulation