List in python: 20 MCQs with answers

list = [1, 2, 3]

Square brackets `[]` are used to create a list in Python. Curly braces create a set, parentheses create a tuple, and angle brackets are not valid.

0

Python uses zero-based indexing, so the first element is at index 0.

40

Negative indexing starts from the end; `-1` refers to the last element, which is 40.

4

The `len()` function returns the number of elements in the list, which is 4.

append()

`append()` adds a single element to the end. `insert()` adds at a specific index, `extend()` adds multiple elements, and `add()` is not a list method.

[1, 2, 3, 4, 5]

The `+` operator concatenates two lists, producing a new list with all elements from both.

[1, 2, 3, 1, 2, 3]

The `*` operator repeats the list the specified number of times, so `[1, 2, 3] * 2` yields `[1, 2, 3, 1, 2, 3]`.

False

Lists are mutable, meaning their elements can be changed after creation.

True

Negative indices count from the end, with `-1` being the last element.

True

The `+` operator concatenates lists, producing a new list.

—

`append()` adds a single element to the end of the list.

—

`len()` returns the length (number of items) of a list.

5 in nums

The `in` keyword is used to check membership in a list. `nums.contains()` and `nums.has()` are not valid Python methods.

[20, 30, 40]

Slicing `[start:end]` includes elements from index `start` up to but not including `end`. So `[1:4]` gives indices 1, 2, 3: `[20, 30, 40]`.

3

`pop()` removes and returns the last element by default. The last element is 3.

remove()

`remove()` removes the first occurrence of a specified value. `pop()` removes by index, `delete()` is not a list method, and `discard()` is for sets.

[2, 4, 6]

This is a list comprehension that multiplies each element by 2, resulting in `[2, 4, 6]`.

False

`insert()` adds an element at a specified index, not necessarily the end. `append()` adds to the end.

True

Slicing creates a new list containing the selected elements.

—

Python lists are heterogeneous, meaning they can store mixed data types.