c - 在 C 中设置 Struct 的字符串成员

Question

我的问题是，当我运行此函数时，我得到的输出与预期不匹配。我正在尝试打印结构“Question”的成员，但由于某种原因，成员“text”和“numAnswers”在应该不同时却相同。

int AddQuestion()
{
    Question * question_added;
    Answer * answer_added;
    char input_buf[256];
    unsigned int num_answers;

    fflush(stdin);

    //Create the memory necessary for the new question.
    printf("Add a new question\n");
    question_added = (Question*)malloc(sizeof(Question));

    //Point the head to our new question.
    question_added->pNext = exam.phead; 
    exam.phead = question_added;

    //Get the question text from the user.
    printf("Please enter the question text below:\n");
    if(fgets(input_buf, sizeof(input_buf), stdin))
    {
        question_added->text = input_buf;
    }


    //Get the number of questions from the user
    printf("How many answers are there?:");
    if(fgets(input_buf, sizeof(input_buf), stdin))
    {
        question_added->numAnswers = atoi(input_buf);   
    }


    printf(question_added->text);
    printf("%d\n", question_added->numAnswers);


    return 1;
};

这是一些示例输出:

MENU:
1. Add a new question.
2. Delete a question.
3. Print the Exam.
4. Quit.
1
Add a new question
Please enter the question text below:
TEST
How many answers are there?:1
1
1

我希望输出是: 测试 1

但两者都给出 1。这很令人困惑。预先感谢您帮助了解这里发生的情况。

编辑:包含结构定义。

typedef struct Question
{
    char* text;
    unsigned int mark;
    Answer** answers;
    unsigned int numAnswers;
    struct Question* pNext;
}Question;

EDIT2:我已经接受了答案，非常感谢所有有用的评论和努力!

Answer 1

此行为是由于同一缓冲区 char input_buf[256]; 使用了两次。

printf("Please enter the question text below:\n");
if(fgets(input_buf, sizeof(input_buf), stdin)) 
{
    question_added->text = input_buf; // when you enter the string, question_added->text holds its address
}


//Get the number of questions from the user
printf("How many answers are there?:");
if(fgets(input_buf, sizeof(input_buf), stdin)) // but you are using the same buffer here
{
    question_added->numAnswers = atoi(input_buf);   
}

因此 input_buf 处的值被第二个输入替换。那是数字。因此，您将获得该号码 2 次!

所以不要再次使用input_buf扫描号码。使用其他一些缓冲区直接使用 num_answers 进行扫描!