c program to check whether input alphabet is a vowel or not

This code checks whether an input alphabet is a vowel or not. Both lower-case and upper-case are checked.

C programming code

#include <stdio.h>
 
main()
{
  char ch;
 
  printf("Enter a character\n");
  scanf("%c", &ch);
 
  if (ch == 'a' || ch == 'A' || ch == 'e' || ch == 'E' || ch == 'i' || ch == 'I' || ch =='o' || ch=='O' || ch == 'u' || ch == 'U')
    printf("%c is a vowel.\n", ch);
  else
    printf("%c is not a vowel.\n", ch);
 
  return 0;
}

Output:

Check vowel using switch statement

#include <stdio.h>
 
main()
{
  char ch;
 
  printf("Enter a character\n");
  scanf("%c", &ch);
 
  switch(ch)
  {
    case 'a':
    case 'A':
    case 'e':
    case 'E':
    case 'i':
    case 'I':
    case 'o':
    case 'O':
    case 'u':
    case 'U':
      printf("%c is a vowel.\n", ch);
      break;
    default:
      printf("%c is not a vowel.\n", ch);
  }              
 
  return 0;
}

Function to check vowel

int check_vowel(char a)
{
    if (a >= 'A' && a <= 'Z')
       a = a + 'a' - 'A';   /* Converting to lower case or use a = a + 32 */
 
    if (a == 'a' || a == 'e' || a == 'i' || a == 'o' || a == 'u')
       return 1;
 
    return 0;
}