(C language) Checking vowels in a String

Question

I am making a vowel checker function. I am somewhat new to the language. I read through that I can not compare a string literal and a character array. Is this true? My program always crashes and I can't see what the problem is. Can anyone explain to me why my code has a problem. Thank you for any kind of input.

void checkVowel(char someString[]){

    int i, len;
    char compare;

    len = strlen(someString);
    printf("%d\n", len);

    printf("you name in all uppercase: ");
    printf(strupr(someString));


    for(i=0; i<len;i++){

        char  compare = someString[i];



        if(compare == "A" || (strcmp(compare,"E"==0))|| compare == "I" || compare == "O" || compare == "U"){
            printf("\n%c", compare);
        }

    }
}

`compare == "A"` --> `compare == 'A'` and `strcmp(compare,"E"==0)` --> `compare == 'E'` Because type of `compare` is `char`, not `char *`. — BLUEPIXY, Jun 21 '17 at 00:10
Thank you for all your inputs, I have found out the answer which is what mr @ScottK have said as well. Thank you for the tips as well — Son Goku, Jun 23 '17 at 00:11

score 1 · Accepted Answer · answered Jun 21 '17 at 00:13

You are using strcmp to compare a character to a C string, that will fail. You should have seen a compiler warning when you tried to do this. Instead of comparing chars and single-character strings, simply compare chars one at a time. No need to use strcmp at all.

Note that using strupr is a non-standard deprecated function provided by Microsoft. Use toupper instead:

#include <ctype.h> // defines toupper and tolower
void checkVowel(char someString[]){
    int i, len;

    len = strlen(someString);
    printf("%d\n", len);

    printf("you name in all uppercase: ");
    printf(strupr(someString));

    for(i=0; i<len;i++) {
       char compare = toupper(someString[i]));
       if ((compare == 'A') || 
           (compare == 'E') || 
           (compare == 'I') || 
           (compare == 'O') ||
           (compare == 'U')) {
            printf("\n%c", compare);
        }
    }
}

Im sorry I was not able to come back to this at all. haha Thank you for your input regarding this. — Son Goku, Apr 16 '18 at 13:48

score 0 · Answer 2 · answered Jun 21 '17 at 00:12

You can try with below , I did not run the code , but i hope it would work :

void checkVowel(char someString[]){

int i, len;
char compare;

len = strlen(someString);
printf("%d\n", len);

printf("you name in all uppercase: ");
printf(strupr(someString));


  for(i=0; i<len;i++){

    char vowelArray[5] = [ 'A','E','I','O','U'];
    char  compare = someString[i];
    int j;
    for (j = 0 ; j < 5; j++){

      if(compare == vowelArray[j]){

       printf("\n%c", compare);

      }
    }       

  }
}

(C language) Checking vowels in a String

2 Answers2