Array Basics: 16 MCQs with answers

A collection of elements of the same data type stored in contiguous memory locations

An array is a fixed-size collection of elements of the same data type stored in contiguous memory locations.

By its index

Array elements are accessed using their index, which represents their position in the array.

They have a fixed size

Arrays have a fixed size determined at creation, which cannot be changed later.

An array of arrays

A multidimensional array is an array of arrays, such as a 2D array representing a matrix.

$O(n)$

An array of size $n$ requires space proportional to $n$, so space complexity is $O(n)$.

0

In many languages like C, C++, Java, and Python, array indices start at 0.

The program may crash or produce undefined behavior

Accessing out of bounds can lead to runtime errors or undefined behavior, as it accesses memory not allocated for the array.

Arrays provide constant-time access to elements by index

Arrays allow direct access to any element using its index in constant time.

False

Arrays are homogeneous; they store elements of the same data type.

False

Static arrays have a fixed size determined at creation and cannot be resized.

$O(1)$

Accessing an array element by index is a constant time operation because the memory address can be calculated directly.

$O(n)$

Inserting at the beginning requires shifting all existing elements one position to the right, which takes linear time.

$O(1)$

Deleting the last element does not require shifting any other elements, so it takes constant time.

$O(n)$

In the worst case, you may need to check every element, resulting in linear time complexity.

$O(\log n)$

Binary search repeatedly divides the search interval in half, resulting in logarithmic time complexity.

Inserting an element at an arbitrary position

Inserting at an arbitrary position requires shifting elements, which is inefficient ($O(n)$) for large arrays.