使用两个不同的函数打印身份证信息，应该在主函数中调用

Question

我想使用两个不同的函数来打印身份证，一个用于来自用户的信息，第二个函数应该显示信息并且应该在主函数中调用。请指出我正在做的错误，因为它没有打印正确的值。

struct card
{
    char name[20];
    int clas;
    char section[20];
    int roll;
};

void info(struct card id)
{
    printf("\n Name: ");
    scanf(" %s", &id.name);
    printf("\nClass: ");
    scanf(" %d", &id.clas);
    printf("\nSection: ");
    scanf(" %s", &id.section);
    printf("\nRoll: ");
    scanf(" %d", &id.roll);
}

void displaydata(struct card id)
{
    printf("\nName: %s", id.name);
    printf("\nClass: %d", id.clas);
    printf("\nSection: %s", id.section);
    printf("\nRoll: %d", id.roll);
}

int main()
{
    struct card id2[4];
    int i;

    for (i = 0; i < 3; i++)
    {
        info(id2[i]);
    }

    for (i = 0; i < 3; i++)
    {
        printf("------");
        printf("student: %d", i + 1);

        displaydata(id2[i]);
    }

    return 0;
}

Answer 1

这里是你的代码修改为使用两个函数的指针：

#include <stdio.h>
#include <stdlib.h>

struct card
{
    char name[20];
    int clas;
    char section[20];
    int roll;
};

void info(struct card *id)
{
    printf("\n Name: ");
    scanf(" %s", &id->name);
    printf("\nClass: ");
    scanf(" %d", &id->clas);
    printf("\nSection: ");
    scanf(" %s", &id->section);
    printf("\nRoll: ");
    scanf(" %d", &id->roll);
}

void displaydata(struct card *id)
{
    printf("\nName: %s", id->name);
    printf("\nClass: %d", id->clas);
    printf("\nSection: %s", id->section);
    printf("\nRoll: %d", id->roll);
}

int main()
{
    struct card id2[4];
    int i;

    for (i = 0; i < (sizeof(id2) / sizeof(id2[0])); i++)
    {
        info(&id2[i]);
    }

    for (i = 0; i < (sizeof(id2) / sizeof(id2[0])); i++)
    {
        printf("------");
        printf("student: %d", i + 1);

        displaydata(&id2[i]);
    }

    return 0;
}

如您所见，我使用 sizeof 获取 id2 数组中的元素数。这比 reader 无法轻易找到意义的 magic 数字要好得多。

您还应该检查 scanf 是否成功。例如：

if (scanf(" %s", &id->name) != 1) {
    fprintf(stderr, "Name not correctly input\n");
    // more code to handle the error, as needed
}

使用两个不同的函数打印身份证信息，应该在主函数中调用

print id card information using two different function and should be called in main function

c

function

struct

card