Example: C Program to Count the Number of Vowels and Consonants

// C Program to Count the Number of Vowels and Consonants
#include <stdio.h>
#include <ctype.h>

// It's the main function of the program
int main() {
    int vowels = 0, consonants = 0, digits = 0, spaces = 0;
    char sentance[1000];

    // Step-1 Take input sentance from User
    printf("Enter a Sentance: ");
    fgets(sentance, sizeof(sentance), stdin);

    // Step-2 Loop over the `sentance` variable to iterate the each character of the sentance
    for (int i = 0; sentance[i] != '\0'; i++) {
        sentance[i] = tolower(sentance[i]);

        // Step-A If Character is a Vowel then increment `vowels` by 1
        if (sentance[i] == 'a' || sentance[i] == 'e' || sentance[i] == 'i' || sentance[i] == 'o' || sentance[i] == 'u') {
            vowels++;
        }

        // Step-B If Character is a Consonant then increment `consonants` by 1
        else if (sentance[i] >= 'a' && sentance[i] <= 'z') {
            consonants++;
        }

        // Step-C If Character is a digit then increment `digits` by 1
        else if (sentance[i] >= '0' && sentance[i] <= '9') {
            consonants++;
        }

        // Step-D If Character is empty space then increment `spaces` by 1
        else if (sentance[i] == ' ') {
            spaces++;
        }
    }

    // Step-3 Final output of the program
    printf("\nVOWELS:: %d\n", vowels);
    printf("CONSONANTS:: %d\n", consonants);
    printf("DIGITS:: %d\n", digits);
    printf("WHITE SPACES:: %d\n", spaces);
    return 0;
}