C语言结构体必知必会

结构体

结构体是一种特殊类型，可以打包其它类型为一种复合类型。在面向对象的概念中，就是一种特殊类。

使用结构体几种形式：

第一种

先定义结构体，然后定义结构体变量。

定义结构体：

struct point1{    int x;    int y;};

定义结构体变量

struct point1 point；

第二种

定义匿名结构体，然后定义结构体变量

struct{    int x;    int y;}point2;

第三种

定义结构体的同时定义结构体变量

struct point3{    int x;    int y;}point;

第四种

用typedef定义结构体

typedef struct point4{    int x;    int y;}t_point;

然后用t_point定义结构体变量

t_point point;

结构体数组

    struct student{        int age;        char *name;    };    struct student ss[10];

结构体指针

    struct student *pst;    pst = &foo;

结构体初始化

有结构体定义

    struct student{        int age;        char *name;    };

第一种

    struct student foo1 = {11, "xiaoming"};    struct student foo2 = {11}

第二种

    struct student foo3 = {.age = 11};

第三种

    struct student foo4 = (struct student){11, "xiaoming"};    struct student foo5 = (struct student){.age = 11};

结构体数组初始化

    struct student ss1[10] = {0};    struct student ss2[10] = {{}, {}, {}};    struct student ss3[10] = {[2] = {}, [3] = {}};    struct student ss4[10] = {[2].age = 10, [3].name = "xiaoming"};

访问结构体成员

使用“.”返回结构体成员

    struct student foo = {11, "xiaoming"};    int age = foo.age;    char *name = foo.name;    printf("age is %d, name is %s\n", age, name);    foo.age = 20;    foo.name = "liyong";    printf("age is %d, name is %s\n", foo.age, foo.name);

当使用结构体指针的时候可以用箭头操作符”->”

    struct student *pst;    pst = &foo;    printf("pst age is: %d and name is %s\n", (*pst).age, (*pst).name);    printf("pst age is: %d and name is %s\n", pst->age, pst->name);