Example: Sort Names Alphabetically using Structures in C

// Sort Names Alphabetically using Structures
#include <stdio.h>   // Required for printf, scanf
#include <string.h>  // Required for strcmp, strcpy

// Define a structure to hold a person's name
struct Person {
    char name[50]; // Assuming names won't exceed 49 characters + null terminator
};

int main() {
    // Step 1: Declare an array of structures
    // Let's sort 5 names for this example
    const int MAX_PEOPLE = 5;
    struct Person people[MAX_PEOPLE];
    int i, j; // Loop counters
    struct Person temp; // Temporary structure for swapping

    // Step 2: Get names from the user
    printf("Enter %d names:\n", MAX_PEOPLE);
    for (i = 0; i < MAX_PEOPLE; i++) {
        printf("Name %d: ", i + 1);
        // Using scanf with %s for simplicity, but consider fgets for names with spaces
        // If using fgets: fgets(people[i].name, sizeof(people[i].name), stdin);
        // Then remove newline if present: people[i].name[strcspn(people[i].name, "\n")] = 0;
        scanf("%s", people[i].name);
    }

    // Step 3: Sort the names using Bubble Sort
    // Outer loop for passes
    for (i = 0; i < MAX_PEOPLE - 1; i++) {
        // Inner loop for comparisons and swaps
        for (j = 0; j < MAX_PEOPLE - 1 - i; j++) {
            // Compare names using strcmp
            // strcmp returns < 0 if first string is smaller (comes first alphabetically)
            // strcmp returns > 0 if first string is larger (comes after alphabetically)
            // strcmp returns 0 if strings are equal
            if (strcmp(people[j].name, people[j+1].name) > 0) {
                // If the current name is alphabetically greater than the next name, swap them
                temp = people[j];         // Store current structure in temp
                people[j] = people[j+1];  // Move next structure to current position
                people[j+1] = temp;       // Move temp structure to next position
            }
        }
    }

    // Step 4: Display the sorted names
    printf("\nNames sorted in alphabetical order:\n");
    for (i = 0; i < MAX_PEOPLE; i++) {
        printf("%s\n", people[i].name);
    }

    return 0;
}