1 #include<stdio.h>
 2 
 3 typedef int i; //为int再重新多取一个名字，i等价于int
 4 
 5 typedef struct student{
 6     int sid;
 7     char sex;
 8 }ST;//为struct student再重新多取一个名字为ST，下面有用到struct student的地方都可以用ST代替
 9 
10 int main(){
11     int a=10;//等价于 i a=10;
12     struct student st;//等价于ST st;
13     struct student *ps;//等价于ST *ps;
14     return 0;
15 }

 1 #include<stdio.h>
 2 
 3 typedef struct student{
 4     int sid;
 5     char sex;
 6     }* PST,STU；//用逗号隔开，PST等价于struct student *，STU代表struct student
 7 
 8 int main(){
 9     STU st;  //struct student st
10     PST ps = &st;  //struct student * ps = &st;
11     return 0;
12 }