Question

 struct phone
 {
      char fname[20];
      char lname[20];
      char pnumber[20];
 };

int main()
{

 int x=0;
 int n;
 char s[100];

 FILE * f;

 f = fopen("phone book","r");

 if (f != NULL)
 {
     printf("file exist !\n");   
     while(!(feof(f)))
     {
           fscanf(f,"%s,%s,%s",s[x].fname,s[x].lname,s[x].pnumber);
           x++;
     }
 }

 printf("1-   add");
 printf("2-   query");
 scanf("%d",&n);

if(n==1)
    printf("%s",s[n].fname);

if(n==2)
    fclose(f);

}

我编写此程序，fscanf

出现问题

错误评论

 'main':|
  request for member 'fname' in something not a structure or union|
  request for member 'lname' in something not a structure or union|
  request for member 'pnumber' in something not a structure or union|
  request for member 'fname' in something not a structure or union|
 : variable 's' set but not used [-Wunused-but-set-variable]|

 : control reaches end of non-void function [-Wreturn-type]|
 ||=== Build finished: 4 errors, 2 warnings (0 minutes, 0 seconds) ===|

Answer 1

s被声明为char s[100];，因此s[x]是char而不是struct phone。您需要将s声明为struct phone s[100];，并且您的第一个问题将会消失。

Answer 2

错误

request for member 'fname' in something not a structure or union|
request for member 'lname' in something not a structure or union|
request for member 'pnumber' in something not a structure or union|
request for member 'fname' in something not a structure or union|
: variable 's' set but not used [-Wunused-but-set-variable]|

更改

char s[100];  // is not a structure. You need to declare it as structure

到

struct phone s[100];

和错误

control reaches end of non-void function [-Wreturn-type]|

作为main的返回类型为int（非void函数，其返回类型不是void），您需要添加return 0;在}的结束括号main之前的陈述。

Answer 3

好吧，编译器是对的。你宣布

char s[100];

并尝试访问其成员，就像它将是一个结构数组。它只是一个char数组。

我想你想做点什么

struct phone s[100];

这将声明一个包含100个struct phone的数组。

另外，请注意虽然（！feof（f））在这种情况下不建议使用：Why is “while ( !feof (file) )” always wrong?

关于写电话簿文件的项目

3 个答案: