Problems counting the number of vowels in an array

Question

#include <stdio.h>

int vowel_count(char n[]){

    int hasil = 0;
    char vowel[] = "aiueoyAIUEOY";
    for (int i = 0; i < 50; i++)
    {
        for (int x = 0; x < 12; x++)
        {
            if (n[i] == vowel[x])
            {
                hasil++;
            }
        }
    }
    return hasil;
}

int main(void){
    int amount;
    char values[50], unknown[10];
    char vowel[] = "AIUEOYaiueoy";
    FILE* fp = fopen("zValues.txt", "r");
    fscanf(fp, "%d", &amount);
    fgets(unknown, 10, fp);
    for (int n = 0; n < amount; n++)
    {
        fgets(values, 50, fp);
        printf("%d ", vowel_count(values));
    }
    fclose(fp);
}

here is the zValues.txt:

5

abracadabra

pear tree

o a kak ushakov lil vo kashu kakao

my pyx

riszky hermawan

when i run the code,it shows:

5 4 13 12 12

see the problem? it's wrong answer" ouput must be like this

5 4 13 2 5

Answer 1

Since your code uses the function, fgets to read the file content, the function vowel_count should not iterate over 50 array characters. Some of the lines (read from the file) may be of different length. Consequently, iterating beyond 50 characters may fetch random values from memory, which may include vowels.

Therefore you just need to adapt the function vowel_count, namely change:

for (int i = 0; i < 50; i++)

to

for (int i = 0; n[i] != '\0'; i++)

Moreover, IMO it is better to do :

for (int x = 0; vowel[x] != '\0'; x++) 

instead of

for (int x = 0; x < 12; x++)

You do not need to hardcode the size of the array because when you write char vowel[] = "aiueoyAIUEOY", the terminal character (i.e. '\0') gets added automatically at the end of it. Although in your case is not very problematic, because the number of vowels will probably remain the same, in other cases, it is prone to bugs.