# Data Structures Arrays - Answers to Arrays related interview questions

## What are Arrays?

An array is a series of elements. These elements are of the same type. Each element can be individually accessed using an index. For e.g an array of integers. Array elements are stored one after another (contiguous) in the memory. An array can have more than one dimension. First element in an array starts with 0.

## Explain two-dimensional array.

An array with two dimensions is called as a two-dimensional array. It is also called as a matrix. In C, a two dimensional array is initialized as int arr[nb_of_rows] [nb_of_columns]. Hence, two dimensional arrays can be considered as a grid. An element in a two dimensional can be accessed by mentioning its row and column. If the array has 20 integer values, it will occupy 80 bytes in memory (assuming 4 bytes for an integer). All of the bytes are in consecutive memory locations, the first row occupying the first 20 bytes, the second the next 20, and so on.

## Define Array of pointers.

An array of pointers is an array consisting of pointers. Here, each pointer points to a row of the matrix or an element. E.g
char *array [] = {“a”, “b”}.
This is an array of pointers to to characters.