- D 编程基础
- D 编程 - 首页
- D 编程 - 概述
- D 编程 - 环境
- D 编程 - 基本语法
- D 编程 - 变量
- D 编程 - 数据类型
- D 编程 - 枚举
- D 编程 - 字面量
- D 编程 - 运算符
- D 编程 - 循环
- D 编程 - 条件语句
- D 编程 - 函数
- D 编程 - 字符
- D 编程 - 字符串
- D 编程 - 数组
- D 编程 - 关联数组
- D 编程 - 指针
- D 编程 - 元组
- D 编程 - 结构体
- D 编程 - 联合体
- D 编程 - 范围
- D 编程 - 别名
- D 编程 - Mixin
- D 编程 - 模块
- D 编程 - 模板
- D 编程 - 不可变对象
- D 编程 - 文件 I/O
- D 编程 - 并发
- D 编程 - 异常处理
- D 编程 - 合约
- D - 条件编译
- D 编程 - 面向对象
- D 编程 - 类与对象
- D 编程 - 继承
- D 编程 - 重载
- D 编程 - 封装
- D 编程 - 接口
- D 编程 - 抽象类
- D 编程 - 有用资源
- D 编程 - 快速指南
- D 编程 - 有用资源
- D 编程 - 讨论
D 编程 - 结构体
结构体是D编程语言中另一种用户自定义的数据类型，它允许您组合不同类型的数据项。
结构体用于表示记录。假设您想跟踪图书馆中书籍的信息。您可能需要跟踪每本书的以下属性：
- 书名
- 作者
- 主题
- 图书ID
定义结构体
要定义结构体，必须使用struct语句。struct语句定义了一种新的数据类型，该类型包含程序的多个成员。struct语句的格式如下：
struct [structure tag] {
member definition;
member definition;
...
member definition;
} [one or more structure variables];
结构体标签是可选的，每个成员定义都是一个普通的变量定义，例如int i; 或float f; 或任何其他有效的变量定义。在结构体定义结束前的分号之前，您可以指定一个或多个结构体变量，这些变量是可选的。以下是声明Books结构体的方法：
struct Books {
char [] title;
char [] author;
char [] subject;
int book_id;
};
访问结构体成员
要访问结构体的任何成员，可以使用成员访问运算符 (.)。成员访问运算符表示为结构体变量名和我们希望访问的结构体成员之间的句点。您将使用struct关键字定义结构体类型的变量。以下示例说明了结构体的用法：
import std.stdio;
struct Books {
char [] title;
char [] author;
char [] subject;
int book_id;
};
void main( ) {
Books Book1; /* Declare Book1 of type Book */
Books Book2; /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "D Programming".dup;
Book1.author = "Raj".dup;
Book1.subject = "D Programming Tutorial".dup;
Book1.book_id = 6495407;
/* book 2 specification */
Book2.title = "D Programming".dup;
Book2.author = "Raj".dup;
Book2.subject = "D Programming Tutorial".dup;
Book2.book_id = 6495700;
/* print Book1 info */
writeln( "Book 1 title : ", Book1.title);
writeln( "Book 1 author : ", Book1.author);
writeln( "Book 1 subject : ", Book1.subject);
writeln( "Book 1 book_id : ", Book1.book_id);
/* print Book2 info */
writeln( "Book 2 title : ", Book2.title);
writeln( "Book 2 author : ", Book2.author);
writeln( "Book 2 subject : ", Book2.subject);
writeln( "Book 2 book_id : ", Book2.book_id);
}
编译并执行上述代码后，将产生以下结果：
Book 1 title : D Programming Book 1 author : Raj Book 1 subject : D Programming Tutorial Book 1 book_id : 6495407 Book 2 title : D Programming Book 2 author : Raj Book 2 subject : D Programming Tutorial Book 2 book_id : 6495700
结构体作为函数参数
您可以像传递任何其他变量或指针一样，以非常类似的方式将结构体作为函数参数传递。您将以与上述示例中相同的方式访问结构体变量：
import std.stdio;
struct Books {
char [] title;
char [] author;
char [] subject;
int book_id;
};
void main( ) {
Books Book1; /* Declare Book1 of type Book */
Books Book2; /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "D Programming".dup;
Book1.author = "Raj".dup;
Book1.subject = "D Programming Tutorial".dup;
Book1.book_id = 6495407;
/* book 2 specification */
Book2.title = "D Programming".dup;
Book2.author = "Raj".dup;
Book2.subject = "D Programming Tutorial".dup;
Book2.book_id = 6495700;
/* print Book1 info */
printBook( Book1 );
/* Print Book2 info */
printBook( Book2 );
}
void printBook( Books book ) {
writeln( "Book title : ", book.title);
writeln( "Book author : ", book.author);
writeln( "Book subject : ", book.subject);
writeln( "Book book_id : ", book.book_id);
}
编译并执行上述代码后，将产生以下结果：
Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 6495407 Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 6495700
结构体初始化
结构体可以通过两种形式初始化，一种使用构造函数，另一种使用{}格式。以下显示了一个示例。
示例
import std.stdio;
struct Books {
char [] title;
char [] subject = "Empty".dup;
int book_id = -1;
char [] author = "Raj".dup;
};
void main( ) {
Books Book1 = Books("D Programming".dup, "D Programming Tutorial".dup, 6495407 );
printBook( Book1 );
Books Book2 = Books("D Programming".dup,
"D Programming Tutorial".dup, 6495407,"Raj".dup );
printBook( Book2 );
Books Book3 = {title:"Obj C programming".dup, book_id : 1001};
printBook( Book3 );
}
void printBook( Books book ) {
writeln( "Book title : ", book.title);
writeln( "Book author : ", book.author);
writeln( "Book subject : ", book.subject);
writeln( "Book book_id : ", book.book_id);
}
编译并执行上述代码后，将产生以下结果：
Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 6495407 Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 6495407 Book title : Obj C programming Book author : Raj Book subject : Empty Book book_id : 1001
静态成员
静态变量只初始化一次。例如，为了使图书具有唯一的ID，我们可以将book_id设为静态并递增图书ID。以下显示了一个示例。
示例
import std.stdio;
struct Books {
char [] title;
char [] subject = "Empty".dup;
int book_id;
char [] author = "Raj".dup;
static int id = 1000;
};
void main( ) {
Books Book1 = Books("D Programming".dup, "D Programming Tutorial".dup,++Books.id );
printBook( Book1 );
Books Book2 = Books("D Programming".dup, "D Programming Tutorial".dup,++Books.id);
printBook( Book2 );
Books Book3 = {title:"Obj C programming".dup, book_id:++Books.id};
printBook( Book3 );
}
void printBook( Books book ) {
writeln( "Book title : ", book.title);
writeln( "Book author : ", book.author);
writeln( "Book subject : ", book.subject);
writeln( "Book book_id : ", book.book_id);
}
编译并执行上述代码后，将产生以下结果：
Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 1001 Book title : D Programming Book author : Raj Book subject : D Programming Tutorial Book book_id : 1002 Book title : Obj C programming Book author : Raj Book subject : Empty Book book_id : 1003
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