Count the Number of Vowels and Consonants in a Char Array

To count the number of vowels and consonants in a character array in C, we iterate through the array and check each character. If the character is a vowel (a, e, i, o, u), we increment the vowel count; otherwise, if it is an alphabetic consonant, we increment the consonant count. This approach ensures that we accurately classify each letter.

Examples to Count Vowels and Consonants

1. Counting Vowels and Consonants in a Character Array

In this example, we will take a predefined character array and iterate through it to count the vowels and consonants.

main.c

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#include <stdio.h>
#include <ctype.h>

int main() {
    char str[] = "Hello World";
    int vowels = 0, consonants = 0;

    for (int i = 0; str[i] != '\0'; i++) {
        char ch = tolower(str[i]);
        
        if (ch >= 'a' && ch <= 'z') {
            if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u')
                vowels++;
            else
                consonants++;
        }
    }

    printf("Vowels: %d\n", vowels);
    printf("Consonants: %d\n", consonants);

    return 0;
}

Explanation:

  1. We declare a character array str[] with the string "Hello World".
  2. Two integer variables, vowels and consonants, are initialized to zero.
  3. We iterate through the array using a for loop until we reach the null terminator '\0'.
  4. Each character is converted to lowercase using tolower() to simplify comparison.
  5. If the character is an alphabetic letter, we check if it is a vowel (a, e, i, o, u) or a consonant.
  6. The respective counter (vowels or consonants) is incremented accordingly.

Output:

Vowels: 3
Consonants: 7

2. Counting Vowels and Consonants from User Input

In this example, we will take a string input from the user and count the number of vowels and consonants.

main.c

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#include <stdio.h>
#include <ctype.h>

int main() {
    char str[100];
    int vowels = 0, consonants = 0;

    printf("Enter a string: ");
    fgets(str, sizeof(str), stdin);

    for (int i = 0; str[i] != '\0'; i++) {
        char ch = tolower(str[i]);

        if (ch >= 'a' && ch <= 'z') {
            if (ch == 'a' || ch == 'e' || ch == 'i' || ch == 'o' || ch == 'u')
                vowels++;
            else
                consonants++;
        }
    }

    printf("Vowels: %d\n", vowels);
    printf("Consonants: %d\n", consonants);

    return 0;
}

Explanation:

  1. We declare a character array str[100] to store user input.
  2. We prompt the user to enter a string and store it using fgets().
  3. A for loop iterates through the input string until the null terminator '\0' is encountered.
  4. The character is converted to lowercase using tolower() for case insensitivity.
  5. If the character is a vowel, we increment the vowels counter; otherwise, if it’s a consonant, we increment the consonants counter.

Output Example:

Enter a string: AppleBanana
Vowels: 5
Consonants: 6

Conclusion

In this tutorial, we explored different ways to count vowels and consonants in a character array in C:

  1. Predefined Character Array: Iterated through a hardcoded string and counted vowels and consonants.
  2. User Input: Allowed the user to enter a string and performed the same count dynamically.