Output of Python Programs | (Dictionary)

Prerequisite: Dictionary
Note: Output of all these programs is tested on Python3
1.What is the output of the following of code?

a = {i: i * i for i in range(6)}
print (a)

Options:
a) Dictionary comprehension doesn’t exist
b) {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25, 6:36}
c) {0: 0, 1: 1, 4: 4, 9: 9, 16: 16, 25: 25}
d) {0: 0, 1: 1, 2: 4, 3: 9, 4: 16, 5: 25}

Ans. (d)

Explanation: The above piece of code written in curly braces generate the whole Dictionary.
2.What is the output of the following of code?

a ={}
a.fromkeys(['a', 'b', 'c', 'd'], 98)
print (a)

Options:
a) Syntax error
b) {‘a’:98, ‘b’:98, ‘c’:98, ‘d’:98}
c) {}
d) {‘a’:None, ‘b’:None, ‘c’:None.’d’:None}

Ans. (c)

Explanation:fromkeys() create a new dictionary with keys from list given to it as an argument and set values of the key, the default value given in it as an argument.
Input:

a ={}
dict = a.fromkeys(['a', 'b', 'c', 'd'], 98)
print (a)
print (dict)

Output:

{}
{'d': 98, 'b': 98, 'a': 98, 'c': 98}

3.What is the output of the following of code?

dict ={}
print (all(dict))

Options:
a) { }
b) False
c) True
d) An exception is thrown

Ans.(c)

Explanation:The all() method returns:

True – If all elements in an iterable are true ot iterable is empty.

False – If any element in an iterable is false.

Input:

a = {}
b = a.fromkeys([1, False, 3], 'True')
print (all(a))
print (all(b))

Output:

True
False

4.What is the output of the following of code?

a = {'geeks' : 1, 'gfg' : 2}
b = {'geeks' : 2, 'gfg' : 1}
print (a == b)

a) True
b) False
c) Error
d) None

Ans. (b)

Explanation:If two dictionary are same it returns true, otherwise it returns false.

5.Which of these about a dictionary is false?
a) The values of a dictionary can be accessed using keys
b) The keys of a dictionary can be accessed using values
c) Dictionaries may or may not be ordered
d) None of the above

Ans.(b)

Explanation: The values of a dictionary can be accessed using keys but the keys of a dictionary can’t be accessed using values.