Check whether a character is a Vowel or Consonant - c

Question

I need to make Check whether a character is a Vowel or Consonant as function and it returns 1 if it's a vowel and returns 0 if it's consonant
That's what I've come up with
#include <stdio.h>
#include <stdlib.h>
int vowel(char c) {
int lowercase, uppercase;
lowercase = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');
uppercase = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');
if (lowercase || uppercase)
return 1;
else
return 0;
}
int main() {
char c;
printf("Enter an alphabet: ");
scanf("%c", &c);
vowel(c);
}
Input: a
Output: Process returned 0

Answer 1

Your function int vowel(char c) looks OK, though for readability and better compiler optimization opportunities I'd use a switch statement, like this:
int vowel(char c) {
switch(tolower(c)){
case 'a':
case 'e':
case 'i':
case 'o':
case 'u':
return 1;
default:
return 0;
}
}
The second observation is that you seem to ignore the result of the function's execution altogether. I could only assume you were supposed to do something with it, like printing out the result. Something along these lines (instead of the v̶o̶w̶e̶l̶(̶c̶)̶;̶ code):
printf("\nThe character '%c' is %sa vowel\n", c, vowel(c) ? "" : "not ");

Answer 2

return type of vowel function is "int". But the function call is not storing the value. Change the function call as below.
int main() {
char c;
printf("Enter an alphabet: ");
scanf("%c", &c);
int flag = vowel(c);
printf("%d",flag); }

Answer 3

#include <stdio.h>
#include <stdlib.h>
int vowel(char c) {
int lowercase, uppercase;
lowercase = (c == 'a' || c == 'e' || c == 'i' || c == 'o' || c == 'u');
uppercase = (c == 'A' || c == 'E' || c == 'I' || c == 'O' || c == 'U');
if (lowercase || uppercase)
return 1;
else
return 0;
}
int main() {
char c;
printf("Enter an alphabet: ");
scanf("%c", &c);
int a=vowel(c);
if(a==1)
printf("vowel");
if(a==0)
printf("consonant");
}

Answer 4

Answering your questions one by one
Firstly,
what you have is a void function called vowel that takes in a char parameter.
When you declare a type of the function, what you are basically doing is telling the system what sort of return type you are expecting from this function. Since you are declaring the function void, you are expecting no return type from it hence, it does not matter what you return there.
Secondly,
when you declare the vowel function int, in your main function you have to store the value of the vowel function in a variable.
Thirdly,
the process returned 0 that you see is mainly the execution of your program saying no errors occurred.
What you probably are looking for is something like this I think,
if (lowercase || uppercase)
printf("1");
else
printf("0");
It's awesome to come up with own solutions, I would also suggest following the solutions given above as they are good coding practice.