C语言学习 结构体

定义一个结构体

struct Company {
  char *name;
  char *id;
  char *location;
}

初始化

1   struct Company company = {.name="imooc", .id="1212121"};

怎么省略struct呢 声明的时候可以这么声明，然后就可以直接用Company 这个关键字来定义company了

1 typedef struct Company {
2     char *name;
3     char *id;
4     char *location;
5   } Company;

typeof 可以简化类型的输入

结构体内部引用另一个结构体

 1 typedef struct Company {
 2     char *name;
 3     char *id;
 4     char *location;
 5   } Company;
 6 
 7   typedef struct Person {
 8     char *name;
 9     int age;
10     char *id;
11     Company *company;
12     Company company2;
13     struct {
14       int extra;
15       char *extra_str;
16     } extra_value;
17     struct Person *partner;
18   } Person;
19 
20   struct Company company = {.name="imooc", .id="1212121"};
21   struct Person person = {.name="bennyhuo", .id="12113322222", .company=&company,
22       .company2={.name="imooc", .id="32323232"}
23   };

全部代码

 1 #include <stdio.h>
 2 #include <io_utils.h>
 3 
 4 int main() {
 5   /*
 6    * struct <结构体名> {
 7    *  <成员类型> <成员名>;
 8    *  ...
 9    * } <结构体变量>;
10    */
11 
12   typedef struct Company {
13     char *name;
14     char *id;
15     char *location;
16   } Company;
17 
18   typedef struct Person {
19     char *name;
20     int age;
21     char *id;
22     Company *company;
23     Company company2;
24     struct {
25       int extra;
26       char *extra_str;
27     } extra_value;
28     struct Person *partner;
29   } Person;
30 
31   struct Company company = {.name="imooc", .id="1212121"};
32   struct Person person = {.name="bennyhuo", .id="12113322222", .company=&company,
33       .company2={.name="imooc", .id="32323232"}
34   };
35 
36   PRINT_INT(person.age);
37   person.age = 30;
38 
39   //person.company->name
40   //person.extra_value.extra
41 
42   PRINT_HEX(&person);
43 
44   Person *person_ptr = &person;
45 
46   puts(person_ptr->name);
47 
48   PRINT_INT(sizeof(Person));
49   PRINT_INT(sizeof(person));
50 
51   struct {
52     char *name;
53     int age;
54     char *id;
55   } anonymous_person;
56 
57   Person person1 = {.name = "andy", .age = 20};
58   PRINT_INT(person1.age);
59 
60   return 0;
61 }

执行结果