Tough Python Questions & Answers on “While and For Loops”.
1. What will be the output of the following Python code?
x = 'abcd' for i in x: print(i) x.upper()
a) a B C D
b) a b c d
c) A B C D
d) error
Answer: b
Clarification: Changes do not happen in-place, rather a new instance of the string is returned.
2. What will be the output of the following Python code?
x = 'abcd' for i in x: print(i.upper())
a) a b c d
b) A B C D
c) a B C D
d) error
Answer: b
Clarification: The instance of the string returned by upper() is being printed.
3. What will be the output of the following Python code?
x = 'abcd' for i in range(x): print(i)
a) a b c d
b) 0 1 2 3
c) error
d) none of the mentioned
Answer: c
Clarification: range(str) is not allowed.
4. What will be the output of the following Python code?
x = 'abcd' for i in range(len(x)): print(i)
a) a b c d
b) 0 1 2 3
c) error
d) 1 2 3 4
Answer: b
Clarification: i takes values 0, 1, 2 and 3.
5. What will be the output of the following Python code?
x = 'abcd' for i in range(len(x)): print(i.upper())
a) a b c d
b) 0 1 2 3
c) error
d) 1 2 3 4
Answer: c
Clarification: Objects of type int have no attribute upper().
6. What will be the output of the following Python code snippet?
x = 'abcd' for i in range(len(x)): i.upper() print (x)
a) a b c d
b) 0 1 2 3
c) error
d) none of the mentioned
Answer: c
Clarification: Objects of type int have no attribute upper().
7. What will be the output of the following Python code snippet?
x = 'abcd' for i in range(len(x)): x[i].upper() print (x)
a) abcd
b) ABCD
c) error
d) none of the mentioned
Answer: a
Clarification: Changes do not happen in-place, rather a new instance of the string is returned.
8. What will be the output of the following Python code snippet?
x = 'abcd' for i in range(len(x)): i[x].upper() print (x)
a) abcd
b) ABCD
c) error
d) none of the mentioned
Answer: c
Clarification: Objects of type int aren’t subscriptable. However, if the statement was x[i], an error would not have been thrown.
9. What will be the output of the following Python code snippet?
x = 'abcd' for i in range(len(x)): x = 'a' print(x)
a) a
b) abcd abcd abcd
c) a a a a
d) none of the mentioned
Answer: c
Clarification: range() is computed only at the time of entering the loop.
10. What will be the output of the following Python code snippet?
x = 'abcd' for i in range(len(x)): print(x) x = 'a'
a) a
b) abcd abcd abcd abcd
c) a a a a
d) none of the mentioned
Answer: d
Clarification: abcd a a a is the output as x is modified only after ‘abcd’ has been printed once.
tough questions on Python,