我可以将 typedef 结构与指针一起使用吗？

Question

Here I wrote some code with a pointer to a structure. I put in some typedef but I don't know how to use it with my pointer structure. I can't find any help on the internet. Always typedef structure, or pointer structure, but not with these 3 involved.

#include<stdio.h>
#include<stdlib.h>

typedef struct student{
    char NAME[20];
    int ID;
    float GRADE;
    char INSTRUCTOR[20];
}student;


int main()
{
    struct student Raf = {"Rafael Sunga", 1775, 1.35, "Kenneth Auxillos"};
    struct student *ptr_Raf; //declaring ptr to a structure
    ptr_Raf = &Raf; //asigning address of variable with & 
    
    printf("Student Name: %s\n", ptr_Raf->NAME);
    printf("ID: %d\n", ptr_Raf->ID);
    printf("Grade: %.2f\n", ptr_Raf->GRADE);
    printf("Instructor: %s\n", ptr_Raf->INSTRUCTOR);

}

Answer 1

#include<stdio.h>
#include<stdlib.h>

typedef struct student //old data type
{
    char NAME[20];
    int ID;
    float GRADE;
    char INSTRUCTOR[20];
}student; //new data type


int main()
{
    student Raf = {"Rafael Sunga", 1775, 1.35, "Kenneth Auxillos"};
    student *ptr_Raf; //declaring ptr to a structure
    ptr_Raf = &Raf; //asigning address of variable with & 
    
    printf("Student Name: %s\n", ptr_Raf->NAME);
    printf("ID: %d\n", ptr_Raf->ID);
    printf("Grade: %.2f\n", ptr_Raf->GRADE);
    printf("Instructor: %s\n", ptr_Raf->INSTRUCTOR);

}

I found the solution, I just removed the "struct" and left the student in, works fine, thannks for the help

Answer 2

The so-called name space rules of C are a bit confusing. When it comes to structs there are 3 different ones that apply: struct tag, struct member and ordinary identifiers.

• struct student is a struct tag.
• typedef... }student; is an ordinary identifier (like any variable name).

Since these exist in different name spaces, we can use the same identifier. When you type struct student in your code, you refer to the struct by tag, if you just type student then the ordinary identifier. As you can tell it gets very confusing when they are given the same name, so we shouldn't do that.

How to declare structs is otherwise a style issue with no obvious right or wrong. The Linux world uses the struct name {... }; style with struct tags. The rest of the world uses the typedef struct {... } name; style.