C结构体指针问题

zjjone1023

C结构体指针问题 [复制链接]

#include
void out(struct person *t)
{
printf("%-10s%2c%4d%7.1f\n",t->name,t->sex,t->age,t->height);
}
void main()
{
struct person
{
char name[20];
char sex;
int age;
float height;
}s[3]={{"yiyi",'g',3,100},{"zhujina",'m',30,180},{"weijing",'g',29,164}};
struct person *p;
for(p=s;p out( p);
}
Compiling...
6.cpp
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2027: use of undefined type 'person'
  C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(2) : see declaration of 'person'
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2227: left of '->name' must point to class/struct/union
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2027: use of undefined type 'person'
  C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(2) : see declaration of 'person'
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2227: left of '->sex' must point to class/struct/union
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2027: use of undefined type 'person'
  C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(2) : see declaration of 'person'
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2227: left of '->age' must point to class/struct/union
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2027: use of undefined type 'person'
  C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(2) : see declaration of 'person'
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(4) : error C2227: left of '->height' must point to class/struct/union
C:\Documents and Settings\Administrator\桌面\C\11\6.cpp(17) : error C2664: 'out' : cannot convert parameter 1 from 'struct main::person *' to 'struct person *'
  Types pointed to are unrelated; conversion requires reinterpret_cast, C-style cast or function-style cast
Error executing cl.exe.

6.exe - 1 error(s), 0 warning(s)
这问题错在哪，我是安照书上写的

David_Lee

试试把下面结构体定义放到函数外面：
struct person
{
char name[20];
char sex;
int age;
float height;
};
main函数里写成：
struct person s[3]={{"yiyi",'g',3,100},{"zhujina",'m',30,180},{"weijing",'g',29,164}};

gaoxiao

for(p=s;p out( p);

 

 

 

也有点问题哟~~~~，貌似不和语法~

孤独剑

for(p=s;p out( p);
应该改成for(p=s;p++;p!='\0' ）out( p);
还有struct person应先声明后引用，因而在void out ()之前就声明该数据结构

leang521

楼上说到点上了

maylove

1. #include <stdio.h>
   #include <stdlib.h>
   struct person
   {
   char name[20];
   char sex;
   int age;
   float height;
   }s[3]={{"yiyi",'g',3,100},{"zhujina",'m',30,180},{"weijing",'g',29,164}};
   void out(struct person *t)
   {
   printf("%-10s%2c%4d%7.1f\n",t->name,t->sex,t->age,t->height);
   }
   
   int main()
   {
   struct person *p;
   
   p = s;
   out(p);
   
   
   //
   while(1);
   //for(p=s;p++;p!='\0' )out( p);
   return 0;
   }
   

复制代码

你的程序不全，所以主函数中为你用while一直在循环。
我的这个在GCC下CODEBLOCK下编译通过。

就像楼上说的，out函数中用到了结构体，可是没有申明。结构体的定义放在最前面。

maylove

书上的例程写成这样。。这书就有点尴尬了。

maylove

原帖由 孤独剑 于 2011-5-2 19:31 发表 for(p=s;p out( p); 应该改成for(p=s;p++;p!='\0' ）out( p); 还有struct person应先声明后引用，因而在void out ()之前就声明该数据结构

for(p=s;p++;p!='\0' ）

这里p怎么也不会等于‘\0’吧

leang521

原帖由 maylove 于 2011-5-2 22:16 发表 for(p=s;p++;p!='\0' ）这里p怎么也不会等于‘\0’吧

呵呵呵，应该是(*P) != '\0'

maylove

原帖由 leang521 于 2011-5-2 22:48 发表 呵呵呵，应该是(*P) != '\0'

(*p)也不会吧..不太明白这个判断有什么用.
(*p)最多也只是指向结构做的第一个元素的第一个字母

leang521

从他的代码看应该是判断结构体结束的。当然这个代码很多问题，这样做是否可靠也要斟酌

zjjone1023

谢谢各位了，2\4楼说对了，应该是把结构体放在前面另外那个循环我没有贴全，应该是for(p=s;p<s+3;p++)out (p)

我已经改过而且结果正确了，程序如下

#include<stdio.h>
struct person
{
char name[20];
char sex;
int age;
float height;
}s[3]={{"yiyi",'g',3,100},{"zhujina",'m',30,180},{"weijing",'g',29,164}};
void out(struct person *t)
{
printf("%-10s%2c%4d%7.1f\n",t->name,t->sex,t->age,t->height);
}
void main()
{
/*struct person
{
char name[20];
char sex;
int age;
float height;
}*/
//struct person s[3]={{"yiyi",'g',3,100},{"zhujina",'m',30,180},{"weijing",'g',29,164}};
struct person *p;
for(p=s;p<s+3;p++) out( p);
}

[ 本帖最后由 zjjone1023 于 2011-5-3 08:57 编辑 ]

zjjone1023

有时候别人给个提示很快就能解决问题，我看书看了半天也没有看出哪不对，书上没有说过要放前面晕

chenzhufly

哇 maylove 真牛气

ddllxxrr

leang521

有些时候认真阅读编译器说明也是必要的。

zjjone1023

我用的是论坛里辛昕给我的Microsoft Visual C++ 6.0，也不知道现在学习用什么好，呵呵

zjjone1023

所言甚是

孤独剑

这里p怎么也不会等于‘\0’吧 [/quote]

正确的是这样的：

   for(p=s;p<s+3;p++)   out( p);

 我查找我们课本了，很确定！

孤独剑

C++去弄几个教学视频看看吧！