Programming MCQs with Answers | C, C++, Java, PHP – Page 10

Question 181 Python

What is the role of the init method in a Python class?

Correct answer C. It initialises a newly created instance, typically setting its attributes

Question 182 Python

How does a @staticmethod differ from a @classmethod in Python?

Correct answer B. A static method receives no implicit first argument, while a class method receives the class as cls

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Question 183 Python

Inside class Account, an attribute is named __balance. Under which name is it actually stored?

Correct answer D. _Account__balance

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Question 184 Python

Which special method should a class define so that the built-in len() works on its instances?

Correct answer A. __len__

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Question 185 Python

Which algorithm does Python 3 use to compute the method resolution order (MRO) for multiple inheritance?

Correct answer B. C3 linearisation

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Question 186 Python

What is the effect of decorating a method with @property?

Correct answer B. The method can be accessed like an attribute, without parentheses

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Question 187 Python

Which exception does an iterator raise from next to signal that it has no more items?

Correct answer D. StopIteration

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Question 188 Python

What turns an ordinary Python function into a generator function?

Correct answer B. Using the yield keyword in its body

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Question 189 Python

Which values can random.randint(1, 6) return?

Correct answer D. Any integer from 1 to 6, including both 1 and 6

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Question 190 Python

Which collections class is designed for fast appends and pops at both ends of a sequence?

Correct answer D. deque

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Question 191 Python

What does collections.Counter(“banana”) evaluate to?

Correct answer B. 3

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Question 192 Python

What does itertools.chain(, ) produce when iterated?

Correct answer A. 1, 2, 3

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Question 193 Python

In Python 3, what is the value of 7 / 2?

Correct answer C. 3.5

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Question 194 DBMS and SQL

Table Emp(id, dept, salary) has rows (1,’HR’,3000), (2,’IT’,5000), (3,’IT’,4000), (4,’HR’,NULL), (5,’Ops’,2000). SELECT COUNT(*), COUNT(salary) FROM Emp; What does this query return?

Correct answer A. 5, 4

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Question 195 DBMS and SQL

Table Emp(id, dept, salary) has rows (1,’HR’,3000), (2,’IT’,5000), (3,’IT’,4000), (4,’HR’,NULL), (5,’Ops’,2000). SELECT AVG(salary) FROM Emp WHERE dept = ‘HR’; What value is returned?

Correct answer D. 3000

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Question 196 DBMS and SQL

Table Emp(id, dept, salary) has rows (1,’HR’,3000), (2,’IT’,5000), (3,’IT’,4000), (4,’HR’,NULL), (5,’Ops’,2000). SELECT dept, SUM(salary) FROM Emp GROUP BY dept HAVING SUM(salary) > 3000 ORDER BY dept; Which rows are returned?

Correct answer B. Only (IT, 9000)

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Question 197 DBMS and SQL

Table Emp(id, dept, salary) has rows (1,’HR’,3000), (2,’IT’,5000), (3,’IT’,4000), (4,’HR’,NULL), (5,’Ops’,2000). SELECT COUNT(DISTINCT dept) FROM Emp; What is the output?

Correct answer D. 3

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Question 198 DBMS and SQL

Table Student(name) has rows ‘amir’, ‘asma’, ‘bilal’, ‘sana’ and ‘aamna’. SELECT COUNT(*) FROM Student WHERE name LIKE ‘a_m%’; What is the result?

Correct answer C. 2

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Question 199 DBMS and SQL

Table Marks(score) has rows 40, 50, 60, 70 and 80. SELECT COUNT(*) FROM Marks WHERE score BETWEEN 50 AND 70; What is returned?

Correct answer B. 3

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Question 200 Python

Where is a docstring written as the first statement of a function stored?

Correct answer A. In the function's __doc__ attribute

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