c - 如何从 C 函数内部将变量扫描到数据结构中

Question

#include <stdio.h>
#define MAX_TITLE_SIZE 20
#define MAX_BOOKS 10

struct Book{
  int _isbn;
  float _price;
  int _year;
  char _title[MAX_TITLE_SIZE];
  int _qty;
};

void displayInventory(const struct Book book[], const int size){

  int i;

  printf("===================================================\n");
  printf("ISBN      Title              Year Price  Quantity\n");
  printf("---------+------------------+----+-------+--------\n");

  //iterate through objects
  if(size == 0){
    printf("The inventory is empty!\n");
    printf("===================================================");
  }
  else{
    for(i = 0; i < size; i++){
      printf("%-10.0d%-18s%5d $%-8.2f%-8d\n", book[i]._isbn, book[i]._title, book[i]._year, book[i]._price, book[i]._qty);
    }
  }
}

void addBook(struct Book book[], int *size){

  if(*size == MAX_BOOKS){
    printf("the inventory is full\n");
  }
  else{

     //increment inventory size
    (*size)++;  //*size will move the pointer to the next in position/hashcode
    //++*size also works



    printf("ISBN:");
    scanf("%d", book[*size]._isbn);
    printf("Title:");
    scanf("%s", book[*size]._title);
    printf("Year:");
    scanf("%d", book[*size]._year);
    printf("Price:");
    scanf("%f", book[*size]._price);
    printf("Quantity:");
    scanf("%d", book[*size]._qty);

    printf("The book is sucessfully added to the inventory.\n");
    printf("\n");
  }
}

int main(void){

  int size = 0;
  struct Book book[MAX_BOOKS];

  book[0]._isbn = 1234;
  printf("Create string: ");
  scanf("%s", book[0]._title);
  book[0]._year = 1992;
  book[0]._price = 192.90;
  book[0]._qty = 2;

  size++;

  addBook(book, &size);

  displayInventory(book, size);
  return 0;
}

所以我正在尝试制作这个簿记系统，我想做的是将一本新书添加到 book[] 数组结构中。

当我尝试在 addBook() 函数中输入一本书的 ISBN 时，整个应用程序以非零状态结束。

如何从函数写入数据结构？如果这是一个愚蠢的问题，我很抱歉，但我已经被这个问题困扰了一段时间了。

我做错了什么？

这是 repl.it 的链接:https://repl.it/JRPH/4

Answer 1

使用scanf时应该引用变量的地址。具体来说， scanf("%d", book[*size]._isbn); -> scanf("%d", &(book[*size]._isbn)); 等等...

看看this .