Example: Toggle Characters using ASCII Values in C

// Toggle Characters using ASCII Values
#include <stdio.h> // For printf, gets
#include <string.h> // For strlen (optional, can use null terminator directly)

#define MAX_LENGTH 100

int main() {
    char str[MAX_LENGTH];

    // Step 1: Prompt user for input string
    printf("Enter a string: ");
    fgets(str, MAX_LENGTH, stdin); // Read string including spaces

    // Remove trailing newline character if present
    str[strcspn(str, "\n")] = 0;

    // Step 2: Iterate through the string to toggle characters
    int i = 0;
    while (str[i] != '\0') {
        // Check if the character is an uppercase letter
        if (str[i] >= 'A' && str[i] <= 'Z') {
            str[i] = str[i] + 32; // Convert to lowercase
        }
        // Check if the character is a lowercase letter
        else if (str[i] >= 'a' && str[i] <= 'z') {
            str[i] = str[i] - 32; // Convert to uppercase
        }
        // If not an alphabet, leave it unchanged
        i++;
    }

    // Step 3: Print the modified string
    printf("Toggled string: %s\n", str);

    return 0;
}