typedef struct student 和 struct student 的区别

struct student
{
int num;
struct student *next;
};

第一个是用typedef 把 struct student 这个结构体类型名字重新定义为student，也就是说struct student和student表示同一个事物，都是一个类型的标识符，

比如 typedef int zhengshu; 就是你把整型int重命名为zhengshu，下面定义：int i; 和 zhengshu i; 两句就是等价的了

例程：

#define ListSize 10

typedef int DataType；

typedef struct{

DataType data【ListSize】；

int length；

}SeqList；

SeqList *L;

L->data =

L->length =

下面两个例程则是他们应用上的区别：

例1：不使用typedef，

//#include
#include
#include //exit
#include
#include

struct pfilename{
char fn[20];
int fn_len;
char *pfn;
int pfn_len;
};

int
main(int argc, char **argv)
{
struct pfilename *pFhead;

pFhead = malloc(sizeof(struct pfilename));
strcpy(pFhead->fn,"iloveyou!");
pFhead->fn_len = strlen(pFhead->fn);
printf("pFhead->fn = %s,length = %d\n",(pFhead->fn),pFhead->fn_len);

//strcpy(pFhead->pfn,"iloveyou!");
pFhead->pfn = "iloveyou!!";
pFhead->pfn_len = strlen(pFhead->pfn);
printf("pFhead->pfn = %s,length = %d\n",(pFhead->pfn),pFhead->pfn_len);

return 0;
}

例2：使用typedef
#include
#include //exit
#include
#include

typedef struct pfilename{
char fn[20];
int fn_len;
char *pfn;
int pfn_len;
}pfilename;



int
main(int argc, char **argv)
{
pfilename *pFhead;

pFhead = malloc(sizeof(pfilename));
strcpy(pFhead->fn,"iloveyou!");
pFhead->fn_len = strlen(pFhead->fn);
printf("pFhead->fn = %s,length = %d\n",(pFhead->fn),pFhead->fn_len);

//strcpy(pFhead->pfn,"iloveyou!");
pFhead->pfn = "iloveyou!!";
pFhead->pfn_len = strlen(pFhead->pfn);
printf("pFhead->pfn = %s,length = %d\n",(pFhead->pfn),pFhead->pfn_len);

return 0;
}