Array in C Language

An array is a collection of elements of the same data type stored in contiguous memory locations. Arrays provide a convenient way to work with a group of related variables. Each element in an array is identified by an index, starting from zero.

Declaring and Initializing an Array:

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

In this example, numbers is an array of integers with a size of 5. The elements are initialized with values 1, 2, 3, 4, and 5.

Types of Arrays in C ( One-Dimensional Array,Multidimensional Array and Character Array (String) ):

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One-Dimensional Array:

An array with a single row or a single column.

Declared and accessed using a single index.

int marks[5] = {85, 90, 75, 92, 88};

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Multidimensional Array:

An array with more than one dimension (rows and columns).

Commonly used for representing matrices.

int matrix[3][3] = {{1, 2, 3}, {4, 5, 6}, {7, 8, 9}};

Access elements using two indices (row and column).

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Character Array (String):

An array of characters used to represent strings.

Strings in C are terminated by a null character '\0'.

char greeting[6] = {'H', 'e', 'l', 'l', 'o', '\0'};

Strings can also be initialized using string literals:

char greeting[] = "Hello";

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Dynamic Array:

Created at runtime using dynamic memory allocation functions (malloc, calloc, realloc).

Allows flexibility in changing the size during program execution.

int* dynamicArray = (int*)malloc(5 * sizeof(int));

Must be freed using free() when no longer needed.

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Common Operations on Arrays

Accessing Elements:

Elements are accessed using their indices.

Indexing starts from 0.

int value = numbers[2]; // Access the third element

Modifying Elements:

Elements can be modified using their indices.

numbers[2] = 10; // Modify the third element

Traversal:

Loop through the array elements for various operations.

for (int i = 0; i < 5; i++) 

{

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

}

Finding Length:

The length of an array is determined by its size.

int length = sizeof(numbers) / sizeof(numbers[0]);

For strings, you can use the strlen function from the <string.h> library.

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One-Dimensional Array:

#include <stdio.h> int main() { // Declaration and initialization of a one-dimensional integer array int numbers[5] = {10, 20, 30, 40, 50}; // Accessing and printing elements of the array printf("One-Dimensional Array:\n"); for (int i = 0; i < 5; i++) { printf("%d ", numbers[i]); } return 0; } output: One-Dimensional Array: 10 20 30 40 50

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Multidimensional Array:

#include <stdio.h> int main() { // Declaration and initialization of a 2D integer array int matrix[3][3] = { {1, 2, 3}, {4, 5, 6}, {7, 8, 9} }; // Accessing and printing elements of the array printf("\n\nMultidimensional Array:\n"); for (int i = 0; i < 3; i++) { for (int j = 0; j < 3; j++) { printf("%d ", matrix[i][j]); } printf("\n"); } return 0; } output: Multidimensional Array: 1 2 3 4 5 6 7 8 9

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Character Array (String):

#include <stdio.h> int main() { // Declaration and initialization of a character array (string) char greeting[] = "Hello"; // Accessing and printing characters of the array printf("\n\nCharacter Array (String):\n"); for (int i = 0; greeting[i] != '\0'; i++) { printf("%c ", greeting[i]); } return 0; } output: Character Array (String): H e l l o

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