Section 3: Arrays and Strings

Lesson 1: Arrays in C

1.1 Declaring and Manipulating Arrays

Arrays in C provide a way to store and manipulate multiple elements of the same data type. They are declared with a fixed size.

Example (Array Declaration and Manipulation): 

#include <stdio.h>

int main() {

    // Array declaration and initialization

    int numbers[5] = {1, 2, 3, 4, 5};

    // Accessing array elements

    printf("Element at index 2: %d\n", numbers[2]);

    // Modifying array elements

    numbers[3] = 10;

    // Displaying modified array

    for (int i = 0; i < 5; i++) {

        printf("%d ", numbers[i]);

    }

    return 0;

}

1.2 Multi-dimensional Arrays

Multi-dimensional arrays in C can have more than one dimension, enabling the creation of tables and matrices.

Example (Multi-dimensional Array):

#include <stdio.h>

int main() {

    // 2D array declaration and initialization

    int matrix[3][3] = {

        {1, 2, 3},

        {4, 5, 6},

        {7, 8, 9}

    };

    // Accessing elements in a 2D array

    printf("Element at row 2, column 1: %d\n", matrix[1][0]);

    return 0;

}

Lesson 2: Strings in C

2.1 String Handling Functions

Strings in C are represented as arrays of characters. The standard library provides various functions for string handling.

Example (String Handling Functions):

#include <stdio.h>

#include <string.h>

int main() {

    // String declaration and initialization

    char greeting[20] = "Hello, ";

    // String concatenation using strcat

    strcat(greeting, "world!");

    // Displaying the concatenated string

    printf("%s\n", greeting);

    return 0;

}

2.2 String Manipulation

C supports a range of operations for manipulating strings, including copying, comparing, and searching.

Example (String Manipulation):

#include <stdio.h>

#include <string.h>

int main() {

    // String declaration and initialization

    char source[] = "Hello";

    char destination[20];

    // Copying a string using strcpy

    strcpy(destination, source);

    // Displaying the copied string

    printf("Copied String: %s\n", destination);

    // Comparing two strings using strcmp

    if (strcmp(source, destination) == 0) {

        printf("The strings are equal.\n");

    } else {

        printf("The strings are not equal.\n");

    }

    return 0;

}

Understanding arrays and strings is fundamental for handling collections of data in C. Practice declaring, manipulating, and accessing elements in arrays. Explore the rich set of string functions available in the standard library for efficient string handling.