ExamAdept

Consider the following Python code:

class Temperature:
    def __init__(self, __celsius):
        self.__celsius = __celsius

    def to_fahrenheit(self):
        return (self.__celsius * 9/5) + 32

What is the purpose of the to_fahrenheit() method?

A:

To retrieve the temperature in Fahrenheit

B:

To set a new temperature in Fahrenheit

C:

To convert the temperature to Fahrenheit

D:

To expose all internal details of the class

Answer: C

The to_fahrenheit() method converts the temperature from Celsius to Fahrenheit, demonstrating encapsulation.

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

class BankAccount:
    def __init__(self, account_number, __balance):
        self.account_number = account_number
        self.__balance = __balance

A:

Use a getter method for 'account_number'

B:

Add a single underscore prefix before 'account_number'

C:

Make 'account_number' a global variable

D:

Add a double underscore prefix before 'account_number'

Answer: D

Adding a double underscore prefix before 'account_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 Wallet:
    def __init__(self, owner, __balance):
        self.owner = owner
        self.__balance = __balance

    def get_balance(self):
        return self.__balance

A:

To create a new instance of the class

B:

To provide controlled access to the 'balance' variable

C:

To define a public variable 'balance'

D:

To allow unrestricted access to the 'balance' variable

Answer: B

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

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

class Inventory:
    __quantity = 0

    def update_quantity(self, quantity):
        Inventory.__quantity += quantity

A:

It improves code maintainability by hiding implementation details

B:

It allows unrestricted access to __quantity

C:

It exposes all internal details of __quantity

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 __quantity.

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Consider the following Python code:

class BankAccount:
    def __init__(self, balance):
        self._balance = balance

    def withdraw(self, amount):
        if amount <= self._balance:
            self._balance -= amount
            return amount
        else:
            return "Insufficient funds"

What encapsulation concept is demonstrated in this code?

A:

Public access specifier

B:

Private access specifier

C:

Protected access specifier

D:

Global variable

Answer: A

The single underscore prefix before 'balance' indicates that it is a public variable, allowing access outside the class.

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Questions for: Encapsulation