typedef的用法

typedef的语法定义就是：typedef existing-type-name new-type-name;也就是给一个已经存在的数据类型起一个别名。

#include <stdio.h>
typedef struct Student
{
	int id;
	char name;
	char sex;
}ST;//一般要大写
int main(void)
{
	struct Student st1;//等价于ST st1;
	struct Student* pst;//等价于ST* pst;
	ST st2;
	st2.id=99;
	printf("%d/n",st2.id);
	return 0;
}

#include <stdio.h>
typedef struct Student
{
	int id;
	char name;
	char sex;
}* PST;//PST等价于struct Student*
int main(void)
{
	struct Student st;
	PST pst=&st;
	pst->id=99;
	printf("%d/n",pst->id);
	return 0;
}

#include <stdio.h>
typedef struct Student
{
	int id;
	char name;
	char sex;
}* PST,ST;//等价于PST代表struct Student*,而ST代表了struct Student;
int main(void)
{
	ST st;//等价于struct Student st;
	PST pst=&st;//struct Student pst=&st;
	pst->id=99;
	printf("%d/n",pst->id);
	return 0;
}