c++ - C++ 代码的意外输出

Question

好的，伙计们...我只是想在这里练习结构，我编写了这个 C++ 代码:

#include <iostream>
#include <cstring>

using namespace std;

struct DATE {
    int year;
    int month;
    int date;
};
struct Book {
    char name[50];
    char author[50];
    int id;
    DATE date;
};

int main() {
     Book book1;
     DATE date1;
     char bookName, bookAuthor,*bookNamePointer = "", *bookAuthorPointer = "";
     int date, year, month;

     cout << "Date Of Publishing? " << endl;
     cin >> date;
     cout << "Month Of Publishing?" << endl;
     cin >> month;
     cout << "Year Of Publishing?" << endl;
     cin >> year;
     date1.year = year;
     date1.month = month;
     date1.date = date;

     cout << "Book Name ? " << endl;
     cin >> bookName;

     printf("********** \n");

     cout << "Book Author ? " << endl;
     cin >> bookAuthor;



     strcpy_s(book1.name, &bookName);
     strcpy_s(book1.author, &bookAuthor);
     printf("Book Name %s \n", book1.name);
     printf("Book Author %s \n", book1.author);
    return 0;
}

很明显，用户只是在这里输入书名、作者等...好吧，它做到了，但是当我输入图书作者时它阻止了我...意味着我无法找到图书作者，并为我的 printf(); 提供了最奇怪的答案；我还没有看到像这样奇怪的东西。我想我需要展示一张图片(顺便说一句，没有警告或错误):

编辑

在我使用 std::string 之后....

#include <iostream>
#include <cstring>
#include <string>

using namespace std;

struct DATE {
    int year;
    int month;
    int date;
};
struct Book {
    char name[50];
    char author[50];
    int id;
    DATE date;
};

int main() {
     Book book1;
     DATE date1;
     std::string bookName, bookAuthor;
     int date, year, month;

     cout << "Date Of Publishing? " << endl;
     cin >> date;
     cout << "Month Of Publishing?" << endl;
     cin >> month;
     cout << "Year Of Publishing?" << endl;
     cin >> year;
     date1.year = year;
     date1.month = month;
     date1.date = date;

     cout << "Book Name ? " << endl;
     cin >> bookName;

     printf("********** \n");

     cout << "Book Author ? " << endl;
     cin >> bookAuthor;



    /* strcpy_s(book1.name, &bookName);
     strcpy_s(book1.author, &bookAuthor);
     printf("Book Name %s \n", book1.name);
     printf("Book Author %s \n", book1.author);*/
    return 0;
}

我实际上没有为图书作者打字……它只是停止了。并说按一个键继续...请帮助!

编辑2

#include <iostream>
#include <cstring>

using namespace std;

struct DATE {
    int year;
    int month;
    int date;
};
struct Book {
    char name[50];
    char author[50];
    int id;
    DATE date;
};

int main() {
     Book book1;
     DATE date1;
     int date, year, month;

     cout << "Date Of Publishing? " << endl;
     cin >> date;
     cout << "Month Of Publishing?" << endl;
     cin >> month;
     cout << "Year Of Publishing?" << endl;
     cin >> year;
     date1.year = year;
     date1.month = month;
     date1.date = date;

     cout << "Book Name ? " << endl;
     cin >> book1.name;

     cout << "Book Author ? " << endl;
     cin >> book1.author;

     cout << "Book Author: " <<book1.author << endl;
     cout << "Book Name: " << book1.name << endl;
     cout << "Date : " << book1.date.month << "/" << book1.date.date << "/" << book1.date.year;

    return 0;
}

我对几乎所有东西都很可靠，但它不允许我为作者打字!!!查看图像以更具描述性:

解决方案

#include <iostream>
#include <cstring>



struct DATE {
    int year;
    int month;
    int date;
};
struct Book {
    char name[50];
    char author[50];
    int id;
    DATE date;
};

int main() {
     Book book1;
     DATE date1;

     std::cout << "Date Of Publishing? " << std::endl;
     std::cin >> book1.date.date;
     std::cout << "Month Of Publishing?" << std::endl;
     std::cin >> book1.date.month;
     std::cout << "Year Of Publishing?" << std::endl;
     std::cin >> book1.date.year;


     std::cout << "Book Name ? " << std::endl;
     std::cin >> book1.name;

     std::cout << "Book Author ? " << std::endl;
     std::cin >> book1.author;

     std::cout << "Book Author: " <<book1.author << std::endl;
     std::cout << "Book Name: " << book1.name << std::endl;
     std::cout << "Date : " << book1.date.month << "/" << book1.date.date << "/" << book1.date.year << std::endl;

    return 0;
}

Answer 1

char表示一个字符。 bookName是单个字符。 cin >> bookName;存储您键入的第一个字符，并且仅存储第一个字符。

然后 strcpy_s(book1.name, &bookName);导致未定义的行为，因为最后一个参数应该指向一个字符串，但是您提供了指向单个字符的指针。

您还为 strcpy_s 使用了错误数量的参数，编译器应该警告你这一点。在运行程序之前始终修复所有编译器警告/错误。还应该有一个 #include对于 printf .

bookAuthor有类似的问题。要解决这些问题，请停止使用字符和字符数组。使用 #include <string>然后 std::string相反。