Array In C Programming

Welcome to this comprehensive guide to one of the most fundamental and versatile data structures in computer programming — arrays. In this tutorial, we will deep dive into arrays in C, covering everything from their definition, declaration, manipulation, to advanced topics like multidimensional arrays and array sorting basic.

Introduction to Arrays in C

An array in C is a data structure that holds a fixed number of elements of the same type. Arrays are used to store data in a structured manner, enabling programmers to write efficient codes, especially when manipulating large amounts of data.

Arrays are advantageous for their ability to save memory space, ease of access to elements, and the ability to pass multiple data to functions using a single array parameter. They are widely used in programming for operations like sorting, searching, and maintaining databases.

Array Declaration and Initialisation

To declare an array in C, you need to specify the data type and the number of elements to hold in the array. Here is the basic syntax:

datatype arrayName[arraySize];

For instance, int numbers[5]; declares an array of integers named ‘numbers’ that can hold 5 elements. 

To initialize an array during declaration, you can specify the array’s elements as follows:

int numbers[5] = {1, 2, 3, 4, 5};

In this case, the array ‘numbers’ is initialised with five integer values.

Accessing Array Elements

C utilizes zero-based indexing, meaning the first element in the array is accessed at index 0. For instance, to access the third element in our ‘numbers’ array, we would use numbers[2].

This can be demonstrated using a simple printf statement:

printf("%d", numbers[2]);

This will output 3.

Array Manipulation

Array manipulation involves altering the contents of an array. This might involve changing the value of a specific element, adding or removing elements, and even creating dynamic arrays.

To modify an array element, you can directly assign a new value using its index:

numbers[0] = 10;


The above line changes the first element of the ‘numbers’ array to 10.

C Programming, being a low-level language, does not provide inbuilt functionality for adding or removing elements to/from arrays. Dynamic arrays can be created using pointers and memory management functions like malloc()calloc()realloc(), and free().

Multidimensional Arrays

Multidimensional arrays are arrays of arrays. The simplest form is the two-dimensional (2D) array. A 2D array is defined in C using the following syntax:

int arrayName[rows][columns];

Using row-major order, each row of the 2D array gets stored in the memory before the next row gets stored.

Sorting Arrays

There are various sorting algorithms like bubble sort, selection sort, and insertion sort that can be used to arrange the elements in an array in a particular order. 

The efficiency of these sorting algorithms is usually measured in terms of time complexity, which indicates how the running time of the algorithm increases with the size of the input.

For example, the bubble sort algorithm, one of the simplest sorting algorithms, sorts the array by repeatedly swapping the adjacent elements if they are in the wrong order. Despite its simplicity, bubble sort has a time complexity of O(n²), making it inefficient for large datasets.


Arrays in C are fundamental data structures that are versatile and easy to use. They provide a structure for efficiently storing and accessing data, making them essential for various mathematical and computational operations.

Remember to follow best practices regarding array declaration, initialization, access, and manipulation. Also, keep in mind the efficiency of array sorting algorithms for managing large datasets.

Keep practicing and experimenting with arrays, and you will soon master this powerful data structure!

Please share this tutorial on your social media channels to help others learn about arrays in C. If you have any questions or other topics you’d like us to cover, please leave a comment below.

Frequently Asked Questions

No, the size of an array is fixed once it’s declared. You may use dynamic arrays instead.

The time complexity of selection sort is O(n²) for worst, average, and best-case scenarios.

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