Array Data Structure Guide

Array Data Structure Guide

What is an Array?

 Image Credit:- Gfg

Example:
Suppose we want to store the ages of five students. We can create an array called studentAges to hold these values:

In this example, studentAges is a one-dimensional array that stores five integers representing the ages of the students.

Need for Array Data Structures

1. Efficient Memory Usage:
   Example: Storing a large number of student records using individual variables would be inefficient and wasteful of memory. Using an array allows us to store all the records in contiguous memory locations.
2. Fast Access:
   Example: Accessing the age of a specific student by their index is a constant-time operation. For instance, studentAges will return the age of the student at index 2, which is 19.
3. Data Organization:
   Example: Arranging student records in an array makes it easier to perform operations like sorting the students based on their ages or searching for a specific student by their age.
4. Foundation for Other Structures:
   Example: Arrays are used to implement more complex data structures like linked lists, where each node contains a value and a reference to the next node.

Types of Array Data Structures

1. One-Dimensional Arrays:
   Example: The studentAges array mentioned earlier is a one-dimensional array.
2. Multi-Dimensional Arrays:
   Example: A two-dimensional array can be used to represent a grid or a table. For instance, a seating arrangement in a classroom can be represented using a two-dimensional array:

In this example, classroomSeating is a two-dimensional array where each row represents a row of seats in the classroom, and each column represents a seat.

3. Jagged Arrays:
   Example: A jagged array is an array of arrays where each sub-array can have a different length. For instance, a jagged array can be used to represent a schedule for different classes with varying numbers of sessions:

In this example, schedule is a jagged array where each sub-array represents a different class with a varying number of sessions.

Array Operations

1. Traversal:
   Example: Printing the elements of the studentAges array:

This loop will print each age in the studentAges array.

2. Insertion:
   Example: Adding a new age to the studentAges array at index 2:

This will shift the elements at indices 2 and higher to the right and insert the value 19 at index 2.

3. Deletion:
   Example: Removing the age at index 3 from the studentAges array:

This will remove the element at index 3 and shift the subsequent elements to the left.

4. Searching:
   Example: Finding the index of the age 21 in the studentAges array using linear search:

This loop will sequentially check each element in the studentAges array until it finds the age 21.

5. Sorting:
   Example: Sorting the studentAges array in ascending order using the built-in sort() method:

After sorting, the studentAges array will be [18, 19, 19, 20, 21, 22].

Applications of Arrays

1. Data Storage:
   Example: Storing a list of product prices in an array for a retail application.
2. Implementing Other Data Structures:
   Example: Using an array to implement a stack data structure, where elements are added and removed from the top of the stack.
3. Mathematical Computations:
   Example: Representing a matrix in linear algebra using a two-dimensional array and performing matrix operations like addition and multiplication.
4. Image Processing:
   Example: Storing pixel data in a two-dimensional array to represent an image and applying image processing algorithms like filtering or edge detection.
5. Database Management:
   Example: Using arrays to store and index data in a database, allowing for efficient retrieval of records based on specific criteria.