how to return a value true if a given char is a vowel and false if not?

[phelle25]

i made a program in else-if statement about this problem.
but my teacher requires to give a return statement about this. i am new with in programming and we had just tackle a return statement and i find it hard to understand. please can u help me. or just give me an idea how to do it.
#include <stdio.h>
#include <conio.h>
int main ()
{
char a,e,i,o,u;
char letter,ans;
printf("\n\nent er another letter(1=yes,0= no)?");
scanf("%d",&ans );
if (ans==1){
printf("\nEnter a letter:");
scanf("%d",&let ter);
if (letter == 'a'){
printf("true"); }
else if (letter == 'e'){
printf("true"); }
else if (letter == 'i'){

printf("true");
}
else if (letter == 'o'){

printf("true");
}

else if (letter == 'u'){

printf("true");

}
else
{
printf("false") ;
}
while (ans==1)

getche ();
return 0;}
}
this is my program in if-else staement.

[JosAH]

I'd do it like this:

int isVowel(char c) {
   return strchr("aeiou", c) != null;
}
 

For an explanation read this link.

kind regards,

Jos

[donbock]

@phelle25
Pull lines 12-23 into a separate function called something like LetterIsVowel. This new function accepts a single input argument (the letter to be tested) and provides an integer output, where 1 means true and 0 means false. Replace the printf statements with return statements. Then modify main to use this new function. Have main print either "true" or "false" based on the return value.

By the way, it helps if you use CODE tags for source code snippets.

[phelle25]

#include <stdio.h>
#include <conio.h>
#include <ctype.h>
#include <stdlib.h>
#define vowels "aeiou"



main ()
{
char isvowel(char vowels);

char letter;
char letter1;
char ans;


do
{
printf("\n\nwan t to enter another letter(1=yes,0= No)?");
scanf("%d",&ans );
if (ans==1)
printf("\nEnter letter:");
scanf("%c",&let ter);
letter1=isvowel (letter);
printf("\nlette r is: %c",letter1);
}
while (ans==1);
}
char isvowel(char vowels)
{
char letter2;

if (letter2 == 'a'){

return ('T');}


else if (letter2 == 'e'){

return ('T');}


else if (letter2 == 'i'){

return ('T');
}

else if (letter2 == 'o'){

return ('T');
}

else if (letter2 == 'u'){

return ('T');






}
else
{
return ('F');
}

}
this is my return statement. but still something is wrong in the part char isvowel(char vowels); can u help me with this.

[JosAH]

Have you read (and understood) my reply #2?

kind regards,

Jos

[donbock]

@phelle25
What do you pass as an argument when you call isvowel?
What is the argument used for in the definition of function isvowel?

Please use CODE tags! Compare the appearance of the source code in post #1 to the same code in post #3.

[whodgson]

Have you you given any thought to using 'switch (char)' and 'case' where the cases would be each vowel (e.g case: 'a') and would print "true". The default case would print"not a vowel"or "false".

[JosAH]

@whodgson
Why is everybody ignoring my reply #2?

kind regards,

Jos ;-)

[donbock]

@JosAH
I stand in awe as I gape agog at reply #2. ;-}

Seriously, my interpretation of the OP's messages is that the fundamental issue is how to write a function and how to invoke it. Making isvowel more efficient is beside the point.

The OP has bigger fish to fry so I wasn't going to bother him with this ... but I can't hold it in any longer. The C Standard reserves certain name patterns for possible use by future versions of the Standard. One of those reserved patterns is the regular expression "^is[a-z]" -- that is, a name that starts with "is" followed by a lowercase letter. The name "isvowel" impinges on this reserved pattern. The OP need not worry about changing the function name; this is not a program that will be used for years and years. Its when you write software that will be maintained for 10+ years that you are advised to be careful of these reserved name patterns.

[JosAH]

@donbock
That's why I wrote isVowel( ... ) with an uppercase V, just to be safe ;-)

kind regards,

Jos