C Program to Check Whether a Character is Vowel or Consonant

1. Introduction

A fundamental exercise in C programming for beginners involves understanding conditional statements through the classification of alphabets. One such common problem is to determine whether a given character is a vowel or a consonant. In this guide, we will learn how to write a C program to check whether a given character is Vowel or Consonant.

2. Program Overview

1. Prompt the user to input a character.

2. Convert the character to lowercase to ensure the check is case insensitive.

3. Use a switch-case statement to determine if the character is a vowel (i.e., 'a', 'e', 'i', 'o', or 'u').

4. If it's a vowel, print the result; if it's not a vowel and is an alphabet, it's a consonant. If it's neither a vowel nor a consonant (not an alphabet), inform the user.

3. Code Program

#include <stdio.h>

int main() {
    char c;
    int isLowercaseVowel, isUppercaseVowel;

    // Asking user to input a character
    printf("Enter a character: ");
    scanf("%c", &c);

    // Check if it's one of the lowercase vowels
    isLowercaseVowel = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');

    // Check if it's one of the uppercase vowels
    isUppercaseVowel = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');

    // Determine the type of the character
    if (isLowercaseVowel || isUppercaseVowel)
        printf("%c is a vowel.", c);
    else if ((c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z'))  // Check if it's an alphabet character
        printf("%c is a consonant.", c);
    else
        printf("%c is not an alphabet character.", c);

    return 0;
}

Output:

Enter a character: e
e is a vowel.

Enter a character: D
D is a consonant.

Enter a character: 1
1 is not an alphabet character.

4. Step By Step Explanation

1. The user is prompted to input a character.

2. Two integer variables, isLowercaseVowel and isUppercaseVowel, are used to store the result of checking whether the character is a lowercase or uppercase vowel, respectively.

3. If the character is either a lowercase or uppercase vowel, it is identified as a vowel.

4. If it's not a vowel but lies within the alphabetic range (either lowercase or uppercase), it's identified as a consonant.

5. Otherwise, the character is neither a vowel nor a consonant, so it's identified as not an alphabet character.