Python OOP Test – 3

1. What will be the output of the following Python code?

class A:
    def __init__(self):
        self.multiply(15)
    def multiply(self, i):
        self.i = 4 * i;
class B(A):
    def __init__(self):
        super().__init__()
        print(self.i)
        
    def multiply(self, i):
        self.i = 2 * i;
obj = B()

2. What will be the output of the following Python code?

class A:
    def __str__(self):
        return '1'
class B(A):
    def __init__(self):
        super().__init__()
class C(B):
    def __init__(self):
        super().__init__()
def main():
    obj1 = B()
    obj2 = A()
    obj3 = C()
    print(obj1, obj2,obj3)
main()

3. What will be the output of the following Python code?

class A:
    def one(self):
        return self.two()    	
    def two(self):
        return 'A'   
class B(A):
    def two(self):
        return 'B'
obj2=B()
print(obj2.two())

4. What will be the output of the following Python code?

class Demo:
    def check(self):
        return " Demo's check "  
    def display(self):
        print(self.check())
class Demo_Derived(Demo):
    def check(self):
        return " Derived's check "
Demo().display()
Demo_Derived().display()

5. Which of the following statements is true?

6. Overriding means changing behaviour of methods of derived class methods in the base class.

7. A class in which one or more methods are only implemented to raise an exception is called an abstract class.

8. What will be the output of the following Python code?

class Demo:
    def __check(self):
        return " Demo's check "
    def display(self):
        print(self.check())
class Demo_Derived(Demo):
    def __check(self):
        return " Derived's check "
Demo().display()
Demo_Derived().display()

9. What will be the output of the following Python code?

class A:
    def __init__(self, x, y):
        self.x = x
        self.y = y
    def __str__(self):
        return 1
    def __eq__(self, other):
        return self.x * self.y == other.x * other.y
obj1 = A(5, 2)
obj2 = A(2, 5)
print(obj1 == obj2)

10. Which of the following best describes polymorphism?

11. What is the biggest reason for the use of polymorphism?

12. What will be the output of the following Python code?

class A:
    def __repr__(self):
        return "1"
class B(A):
    def __repr__(self):
        return "2"
class C(B):
    def __repr__(self):
        return "3"
o1 = A()
o2 = B()
o3 = C()
print(obj1, obj2, obj3)

13. What is the use of duck typing?

14. What will be the output of the following Python code?

class A:
    def __init__(self):
        self.multiply(15)
        print(self.i)

    def multiply(self, i):
        self.i = 4 * i;
class B(A):
    def __init__(self):
        super().__init__()
        
    def multiply(self, i):
        self.i = 2 * i;
obj = B()

15. What will be the output of the following Python code?

class Demo:
    def __init__(self):
        self.x = 1
    def change(self):
        self.x = 10
class Demo_derived(Demo):
    def change(self):
        self.x=self.x+1
        return self.x
def main():
    obj = Demo_derived()
    print(obj.change())

main()