Hackerrank Object-Oriented Programming Basics 4

Question 1

What is the purpose of the @property decorator?

Accepted Answer

It makes an attribute read-only by default and allows controlled access via a method

Answer

@property allows a method to be accessed like an attribute, enabling getter logic without calling it with parentheses.

Question 2

What does 'polymorphism' mean in the context of Python OOP?

Accepted Answer

Different classes can define the same method name with different behavior

Answer

Polymorphism allows different classes to implement the same interface (method name), with each class providing its own behavior.

Question 3

Which naming convention indicates a 'protected' attribute in Python?

Accepted Answer

_attribute (single underscore)

Answer

A single leading underscore (_attr) is a convention signaling that an attribute is intended for internal use, though it's not enforced by Python.

Question 4

What is name mangling in Python?

Accepted Answer

Double-underscore prefix causes Python to rewrite the attribute name to _ClassName__attr

Answer

Python applies name mangling to __attr inside a class, storing it as _ClassName__attr to avoid accidental access from subclasses.

Question 5

What will this print?
class Animal:
    def speak(self):
        return 'Generic'
class Cat(Animal):
    def speak(self):
        return 'Meow'
print(Cat().speak())

Accepted Answer

Meow

Answer

Cat overrides Animal.speak(), so Cat().speak() calls Cat's version and returns 'Meow'.

(Hackerrank) HackerRank Python Certification Practice Test

(Hackerrank) HackerRank Python Certification Practice Test

Hackerrank Object-Oriented Programming Basics 4