c结构体定义

Using the struct keyword we can create complex data structures using basic C types.

使用struct关键字，我们可以使用基本的C类型创建复杂的数据结构。

A structure is a collection of values of different types. Arrays in C are limited to a type, so structures can prove to be very interesting in a lot of use cases.

结构是不同类型的值的集合。 C语言中的数组仅限于一种类型，因此在许多用例中，结构都可以证明是非常有趣的。

This is the syntax of a structure:

这是结构的语法：

struct 
     
       {  //...variables};
     

Example:

例：

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

You can declare variables that have as type that structure by adding them after the closing curly bracket, before the semicolon, like this:

您可以通过在大括号后，分号之前添加变量来声明具有该结构类型的变量，如下所示：

struct person {  int age;  char *name;} flavio;

Or multiple ones, like this:

或多个，例如：

struct person {  int age;  char *name;} flavio, people[20];

In this case I declare a single person variable named flavio, and an array of 20 person named people.

在这种情况下，我宣布一个person命名的变量flavio ，和20的阵列person命名的people 。

We can also declare variables later on, using this syntax:

我们也可以稍后使用以下语法声明变量：

struct person {  int age;  char *name;};struct person flavio;

We can initialize a structure at declaration time:

我们可以在声明时初始化一个结构：

struct person {  int age;  char *name;};struct person flavio = { 37, "Flavio" };

and once we have a structure defined, we can access the values in it using a dot:

一旦定义了结构，就可以使用点访问其中的值：

struct person {  int age;  char *name;};struct person flavio = { 37, "Flavio" };printf("%s, age %u", flavio.name, flavio.age);

We can also change the values using the dot syntax:

我们还可以使用点语法更改值：

struct person {  int age;  char *name;};struct person flavio = { 37, "Flavio" };flavio.age = 38;

Structures are very useful because we can pass them around as function parameters, or return values, embedding various variables within them, and each variable has a label.

结构非常有用，因为我们可以将它们作为函数参数传递或返回值，将各种变量嵌入其中，每个变量都有一个标签。

It’s important to note that structures are passed by copy, unless of course you pass a pointer to a struct, in which case it’s passed by reference.

请务必注意，结构是通过copy传递的 ，除非您当然传递了指向结构的指针，在这种情况下，结构是通过引用传递的。

Using typedef we can simplify the code when working with structures.

使用typedef我们可以在处理结构时简化代码。

Let’s make an example:

让我们举个例子：

typedef struct {  int age;  char *name;} PERSON;

The structure we create using typedef is usually, by convention, uppercase.

按照约定，我们使用typedef创建的结构通常是大写的。

Now we can declare new PERSON variables like this:

现在我们可以这样声明新的PERSON变量：

PERSON flavio;

and we can initialize them at declaration in this way:

我们可以通过以下方式在声明时初始化它们：

PERSON flavio = { 37, "Flavio" };

翻译自:

c结构体定义