Array

An array is a data structure that stores a fixed-size sequential collection of elements of the same type. The elements are stored in contiguous memory locations, allowing for efficient access and manipulation. The total number of elements in an array is its length.

Types of Array Sizes

There are basically two types of array sizes:

• Static Array: In this type of array, memory is allocated at compile time having a fixed size of it. We cannot alter or update the size of this array.

• Dynamic Array: In this type of array, memory is allocated at run time but not having a fixed size. Suppose, a user wants to declare any random size of an array, then we will not use a static array, instead of that a dynamic array is used in hand. It is used to specify the size of it during the run time of any program.

Types of Arrays

There are four types of arrays:

• One-Dimensional Arrays: A one-dimensional array is a kind of linear array. It involves single sub-scripting. The [] (brackets) is used for the subscript of the array and to declare and access the elements from the array.

• Two-Dimensional Arrays: An array involving two subscripts [] [] is known as a two-dimensional array. They are also known as the array of the array. Two-dimensional arrays are divided into rows and columns and are able to handle the data of the table.

• Multi-dimensional Arrays: A multi-dimensional array is an array with more than two dimensions. It can be thought of as an array of arrays of arrays, and so on.

• Jagged array: A jagged array is an array of arrays, where each sub-array can have a different number of elements.

Example

// Array example
var simple_array = [1, 2, 3, 4, 5]; 
// Jagged Array
var jagged_array = [[1, 2, 3], [4, 5], [6, 7, 8, 9]];
//Two Dimensinal Array ( 2 Rows,3 Columns)
var two_dimensinal = new int[2,3]
                    {
                        {2, 5, 9},
                        {6, 9, 15}
                    };

Operations of the array in data structure

There are some operations of the array in the data structure:

• Access: It get an element at a particular index.

• Insertion: It is used to add an element at a particular index.

• Deletion: It is used to delete an element from a particular index.

• Search: It is used to search an element using the given index or by the value.

• Update: It updates an element at a particular index.

• Sort: Arranges elements in a specific order.

Complexity Table

Operation	Best Case	Average Case	Worst Case
Access	O(1)	O(1)	O(1)
Search	O(1)	O(N)	O(N)
Insertion (at the end)	O(1)	O(1)	O(N)
Insertion (at the beginning or middle)	O(1)	O(N)	O(N)
Deletion (from the end)	O(1)	O(1)	O(1)
Deletion (from the beginning or middle)	O(1)	O(N)	O(N)