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

#include <stdio.h>

int 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 of Program:

Enter a character

E is a vowel.

Check vowel using switch statement

#include <stdio.h>

int main()

{

  char ch;

  printf("Input 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;

}

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