Classes & Instances — Series 2

Preview — 3 of 10 questions

What is the output of the following code?

javascript

class Foo:
    def __init__(self):
        return 42

f = Foo()

ATypeError: __init__() should return None, not 'int'

Bf = Foo() succeeds, and f is simply the integer 42.

Cf = Foo() succeeds normally; the return 42 is silently ignored.

DSyntaxError: 'return' outside function

What is the output of the following code?

javascript

class A:
    value = "A"

class B:
    value = "B"

class C(A, B):
    pass

print(C.value)
print(C().value)

AA, then B

BB, then B

CA, then A

DAttributeError: 'C' object has no attribute 'value'

What is the output of the following code?

javascript

class Animal:
    pass

class Dog(Animal):
    pass

d = Dog()
print(isinstance(d, Animal))
print(type(d) == Animal)
print(type(d) == Dog)

ATrue, True, True

BTrue, False, True

CFalse, False, True

DTrue, False, False

Answer all 10 questions (7 more), see explanations for every answer, and track your score.