🔀⚡Beginner

Check Whether Character is Vowel or Consonant

Character classification

Vowels are the letters A, E, I, O, U (and their lowercase versions). All other alphabets are consonants. This program demonstrates character comparison and logical operators.

C Program to Check Vowel or Consonant

vowel_consonant.c

1#include <stdio.h>
2#include <ctype.h>  // For tolower()
3
4int main() {
5    char ch;
6    
7    printf("Enter a character: ");
8    scanf("%c", &ch);
9    
10    // Convert to lowercase for easier comparison
11    ch = tolower(ch);
12    
13    // Check if it's an alphabet first
14    if (ch >= 'a' && ch <= 'z') {
15        // Check if vowel
16        if (ch == 'a' || ch == 'e' || ch == 'i' || 
17            ch == 'o' || ch == 'u') {
18            printf("'%c' is a Vowel\n", ch);
19        } else {
20            printf("'%c' is a Consonant\n", ch);
21        }
22    } else {
23        printf("'%c' is not an alphabet\n", ch);
24    }
25    
26    return 0;
27}

Output

Enter a character: E

'e' is a Vowel

Code Breakdown

tolower(ch)

Converts uppercase to lowercase. Makes comparison easier - we only check a, e, i, o, u instead of both cases.

ch >= 'a' && ch <= 'z'

Uses logical AND (&&) to check if character is between 'a' and 'z' (an alphabet).

ch == 'a' || ch == 'e' || ...

Uses logical OR (||) to check if character matches ANY vowel.

Logical Operators

Operator	Name	Description
&&	AND	TRUE if BOTH conditions are true
\|\|	OR	TRUE if ANY condition is true
!	NOT	Reverses the condition

Alternative: Using Switch

main.c

1switch(tolower(ch)) {
2    case 'a': case 'e': case 'i': case 'o': case 'u':
3        printf("Vowel");
4        break;
5    default:
6        printf("Consonant");
7}