C Program to Check if a Character is Vowel or Constant

In this article, we will learn How to determine or check if a character is vowel or constant or number or a special character using the C programming language.

To solve this problem, we need some fundamental concepts of C programming (the main function, if-else, variables, I/O, etc). Also, we have to know the iteration technique of alphabet and numbers in C.

Algorithm – Check if a Character is Vowel or Constant

• We will write all of our business logic inside our main function.
• Declare a character variable called ch inside the main function.
• After that, scan/ask the user for taking a character input and put it into the ch variable.
• Now, first, check if the input character is alphabet or not. If it is an alphabet then write another check if it is a vowel, display the character and also display it is a vowel. If it is not a vowel then display the character and display it is constant.
• At the first check, if it is not an alphabet, then check if it is a number or not. If it is a number then display the number.
• If the number checking logic fails to determine the number then simply print out “You entered a special character.”

C Program to Check if a Character is Vowel or Constant

#include <stdio.h>
int main() {
    char ch;

    printf("Enter a Character: ");
    scanf("%c", &ch);

    if ((ch >= 'a' && ch <= 'z') || (ch >= 'A' && ch <= 'Z')) {
        printf("The charater '%c' is an alphabet.", ch);

        if(ch == 'A' || ch == 'a' || ch == 'E' || ch == 'e' || 
        ch == 'I' || ch == 'i' || ch == 'O' || ch == 'o' || 
        ch == 'U' || ch == 'u'
        ) {
            printf(" And it is a Vowel!\n");
        } else {
            printf(" And it is a Constant!\n");
        }
    } else if (ch >= '0' && ch <= '9') {
        printf("The character '%c' is a number.\n", ch);
    } else {
        printf("You entered a special character.\n");
    }

    return 0;
}

1. Copy and paste the code in a file and save with .c file extension. Then run it with your favorite IDE to see the output;

General Learning Output (GLO)

• Uses of the declaration of C main function.
• Declaring character variable in C programming.
• Scanf function uses and declaration syntax along with character variable input.
• Basic conditional statement and its syntax used in C programming with complex logic making with AND (&&), OR (||) operator.
• Lines are manually wrappable, Which means we can break any line when a single expression is so large. So for good readability, we can break the line just like the above code.
• Displaying info to the console using printf function.