警告：传递参数从指针生成整数而不进行强制转换

Question

我为书店程序编写了一些代码，其中包含一个函数，用于扫描输入的每本书的详细信息。但是，我得到了一个警告（34：4），这个警告意味着要通过这本书的标题。我假设它与标题是唯一包含字符的变量有关，但我不确定为什么这是一个问题。这是我的代码：

#include <stdio.h>

#define MAX_BOOKS 10 //Maximum number of books that exist in an inventory
#define MAX_TITLE_SIZE 20//Maximum number of characters in a book title

struct Book { //Declare struct Book
    int _isbn; //International Standard Book Number
    float _price; //Book price
    int _year; //Publication year
    char _title[MAX_TITLE_SIZE]; //Book title
    int _qty; //Book Quantity
};

int menu();
void displayInventory(const struct Book book[], const int size);
void searchInventory(const struct Book book[], const int isbn, const int size);
void addBook(struct Book book[], int *size);
void checkPrice(const struct Book book[], const int size);
/* main program */
int main(void) {

    struct Book book[MAX_BOOKS]; //An array of Book representing the inventory
    int size = 0; //Number of books in the inventory. The inventory is initially empty

    //Display a welcome message:
    printf("Welcome to the book store\n");
    printf("=========================\n");

    int select = menu();
    switch (select)
    {
        case 0: //Exit the program
            displayInventory(book, &size);
            break;

        case 1: //Display the inventory
            break;

        case 2: //Add a book to the inventory
            addBook(book, &size);
            break;

        case 3: //Check price
            break;
        default:
            printf("Invalid input, try again\n");
            break;
    }

    return 0;
}

int menu()
{

        int option = 0;

        printf("Please select from the following options:\n");
        printf("1) Display the inventory\n");
        printf("2) Add a book to the inventory\n");
        printf("3) Check price.\n");
        printf("0) Exit\n");
        printf("Select ");

        scanf("%d", &option);


    return option;
}

void displayInventory(const struct Book book[], const int size)
{
    int i = 0;

    if (size > 0) {
    printf("===================================================\n");
    printf("ISBN      Title               Year Price   Quantity\n");
    printf("---------+-------------------+----+-------+--------\n");
    for (i = 0; i < size; i ++) {
    printf("%-10d%-20s%-5d$%-8.2f%-8d", book[i]._isbn, book[i]._title,    book[i]._year, book[i]._price, book[i]._qty);
        }
    }
    else {
        printf("The inventory is empty!");
    }
}


void searchInventory(const struct Book book[], const int isbn, const int size)
{
    printf("Not implemented");

    return;
}

void addBook(struct Book book[], int *size)
{
    if(*size== MAX_BOOKS) {
        printf("the inventory is full.");
    }

    else {       
        printf("ISBN\n");
        scanf("%d", &book[*size]._isbn);
        printf("Title\n");
        scanf("%c", &book[*size]._title);
        printf("Price\n");
        scanf("%lf", &book[*size]._price);
        printf("Year\n");
        scanf("%d", &book[*size]._year);
        printf("Qty\n");
        scanf("%d", &book[*size]._qty); 
        printf("Book successfully added to inventory\n");

        *size++;
        }


}

void checkPrice(const struct Book book[], const int size)
{
    printf("Not implemented");

    return;
}