An array is a collection of items of the same variable type that are stored at contiguous memory locations. It is one of the most popular and simple data structures used in programming.
Basic terminologies of Array
- Array Element: Elements are items stored in an array.
- Array Index: Elements are accessed by their indexes. Indexes in most of the programming languages start from 0.
Memory representation of Array
In an array, all the elements or their references are stored in contiguous memory locations. This allows for efficient access and manipulation of elements.
Declaration of Array
Arrays can be declared in various ways in different languages. For better illustration, below are some language-specific array declarations:
// This array will store integer type element
int arr[5];
// This array will store char type element
char arr[10];
// This array will store float type element
float arr[20];
// This array will store integer type element
int arr[5];
// This array will store char type element
char arr[10];
// This array will store float type element
float arr[20];
// This array will store integer type element
int arr[];
// This array will store char type element
char arr[];
// This array will store float type element
float arr[];
# In Python, all types of lists are created same way
arr = []
// This array will store integer type element
int[] arr;
// This array will store char type element
char[] arr2;
// This array will store float type element
float[] arr3;
// JS code
let arr = []
Initialization of Array
Arrays can be initialized in different ways in different languages. Below are some language-specific array initialization:
int arr[] = { 1, 2, 3, 4, 5 };
char arr[5] = { 'a', 'b', 'c', 'd', 'e' };
float arr[10] = { 1.4, 2.0, 24, 5.0, 0.0 };
int arr[] = { 1, 2, 3, 4, 5 };
char arr[5] = { 'a', 'b', 'c', 'd', 'e' };
float arr[10] = { 1.4, 2.0, 24, 5.0, 0.0 };
int arr[] = { 1, 2, 3, 4, 5 };
char arr[] = { 'a', 'b', 'c', 'd', 'e' };
float arr[] = { 1.4f, 2.0f, 24f, 5.0f, 0.0f };
# This list will store integer type elements
arr = [1, 2, 3, 4, 5]
# This list will store character type elements (strings in Python)
arr = ['a', 'b', 'c', 'd', 'e']
# This list will store float type elements
arr = [1.4, 2.0, 24.0, 5.0, 0.0] # All float values
int[] arr = { 1, 2, 3, 4, 5 };
char[] arr = { 'a', 'b', 'c', 'd', 'e' };
float[] arr = { 1.4f, 2.0f, 24f, 5.0f, 0.0f };
let arr = [ 1, 2, 3, 4, 5 ];
let arr = [ 'a', 'b', 'c', 'd', 'e' ];
let arr = [ 1.4, 2.0, 24, 5.0, 0.0 ];
Why do we Need Arrays?
Assume there is a class of five students and if we have to keep records of their marks in examination then, we can do this by declaring five variables individual and keeping track of records but what if the number of students becomes very large, it would be challenging to manipulate and maintain the data. So we use an array of students.
Types of Array
Operations on Array
- Traversal in Array
- Insertions : At Beginning, At given position and At the end.
- Deletion : From Beginning, Given Position, First Occurrence, All occurrences and From End
- Searching : Linear Search and Binary Search