typedef的用法

为数据类型取别名

#include<stdio.h>

typedef int i; //为int再重新多取一个名字，i等价于int

typedef struct student{
    int sid;
    char sex;
}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

int main(){
    int a=10;//等价于 i a=10;
    struct student st;//等价于ST st;
    struct student *ps;//等价于ST *ps;
    return 0;
}

#include<stdio.h>

typedef struct student{
    int sid;
    char sex;
    }* PST,STU；//用逗号隔开，PST等价于struct student *，STU代表struct student

int main(){
    STU st;  //struct student st
    PST ps = &st;  //struct student * ps = &st;
    return 0;
}