Incompatible pointer type warnings in array of strings on Netbean IDE

Question

I'm writing a program to input book information using typedef and function.

Here is my declaration using typedef:

typedef struct {
    char name[1000], author[1000], publisher[1000], description[1000], ISBN[15];
} book;

Here is the function used to add book info:

void addBook(int* n, book list[1000]) {
    printf("Enter number of book you want to add: ");
    fpurge(stdin);
    scanf("%d", n);
    int i;
    for (i = 0; i < *n; i++) {
        printf("Book title: ");
        fpurge(stdin);
        gets(list[i].name);
        printf("Book author: ");
        fpurge(stdin);
        gets(list[i].author);
        printf("Publisher: ");
        fpurge(stdin);
        gets(list[i].publisher);
        printf("Description: ");
        fpurge(stdin);
        gets(list[i].description);
        printf("ISBN: ");
        fpurge(stdin);
        gets(list[i].ISBN);
    }
}

And the final is main:

int main(int argc, char** argv) {
    int n, list[1000];
    addBook(&n, list);
    return (EXIT_SUCCESS);
}

So when I tried to run, it worked. However, the compiler showed me two warning:

warning: passing argument 2 of 'addBook' from incompatible pointer type [-Wincompatible-pointer-types]
expected 'book *' but argument is of type 'int'

My question is: Are these warnings considered as errors? If yes, what is the correct solution? If no, why the compiler showed it?

P/s: I use Netbean IDE.

alk alk · Accepted Answer · 2016-12-11T12:09:47

Are these warnings considered as errors? I

In C most every warning if ignored leads to more or less fatal behaviour sooner or later. In may such cases the infamous Undefined Behaviour is invoked, which means that from that moment on anything can happen. The code might work, or not, sometimes only, or just Mondays or ...

So take these warnings serious and fix your code accordingly.

To do so change

 int n, list[1000];

to be

 int n;
 book list[1000];

Incompatible pointer type warnings in array of strings on Netbean IDE

2 Answers