关于文件的读写问题

发布网友发布时间：2022-04-26 00:29

共1个回答

热心网友时间：2023-10-24 19:26

我大致看了一下，找到一个很明显到错误！！！
void input()
{
int i;

printf("please ipiut the information of the students:\n");
for(i=0;i<M;i++)
scanf("%s%d%d", &stu[i].name, &stu[i].num, &stu[i].score);//把M换成i,因为你到循环变量是i
printf("the information has been inported.\n\n");

}
void load(char name[])
{
FILE *p;
struct student stu1[M];
int i;

p=fopen( name,"wb");

printf("the information of the file is :\n");

fread( stu1, sizeof(struct student), M, p);
for (i=0;i<M;i++)
printf("%s%d%d\n", stu1[i].name, stu1[i].num, stu1[i].score); //这里输出到时候也一样

fclose (p);
}

补充回答：
void load(char name[])
{
FILE *p;
struct student stu1[M];
int i;

p=fopen( name,"wb");//你的这个函数是读取文件数据，打开方式应为"rb","wb"是写的方式

printf("the information of the file is :\n");

fread( stu1, sizeof(struct student), M, p);
for (i=0;i<M;i++)
printf("%s%d%d\n", stu1[M].name, stu1[M].num, stu1[M].score);

fclose (p);
}

还有你的这个程序有很多地方容易导致错误！比如说scanf("%s%d%d", &stu[M].name, &stu[M].num, &stu[M].score); name是字符数组的数组名，本身就代表该数组的首地址，没必要再取其地址了！虽然你这样写运行时没有问题，但难保你能用的顺利！fread和fwrite函数处理数据的效率比较高，但是这两个函数除非你用的熟练，否则很容易就出错！而且fwrite函数写入的是二进制数据，没办法核对你写入文件的数据是否正确！所以对于小程序来说尽量使用fscanf和fprinf两个函数处理数据，易于检查！

程序我帮你改好了，你自己试一下！
#include "stdio.h"
#include "conio.h"
#define M 3

struct student
{
char name [20];
int num;
int score;
} stu[M];

void main()
{
void input();
void save(char name[]);
void load(char name[]);

char name[20];

input();

printf("please input the name of the saved file:");
scanf("%s",name);

save(name);
load(name);

getch();
}
void input()
{
int i;

printf("please ipiut the information of the students:\n");
for(i=0;i<M;i++)
scanf("%s%d%d", stu[i].name, &stu[i].num, &stu[i].score);
printf("the information has been inported.\n\n");
}
void save(char name[])
{
int i;
FILE *p;
p=fopen( name,"wb");
fwrite( stu, sizeof(struct student), M, p);
printf("the file has been saved.\n\n");

fclose(p);
}

void load(char name[])
{
FILE *p;
struct student stu1[M];
int i;

p=fopen( name,"rb");

printf("the information of the file is :\n");

fread( stu1, sizeof(struct student), M, p);
for (i=0;i<M;i++)
printf("%4s%4d%4d\n", stu1[i].name, stu1[i].num, stu1[i].score);

fclose (p);
}