Go 结构
Go数组允许你定义可以容纳相同种类的多个数据项的变量。结构是Go编程中可用的另一种用户定义的数据类型，它允许你组合不同种类的数据项。
结构用于表示记录。假设你想跟踪图书馆中的书籍。你可能需要跟踪每本书的以下属性：
标题
作者
主题
书籍ID
在这种情况下，结构非常有用。
定义结构
要定义结构，你必须使用type和struct语句。 struct语句定义一个新的数据类型，该程序具有多个成员。在我们的例子中，type语句将名称与struct绑定在一起。 struct语句的格式如下：
type struct_variable_type struct {
member definition;
member definition;
...
member definition;
}一旦定义了结构类型，就可以使用以下语法将其用于声明该类型的变量。
variable_name := structure_variable_type {value1, value2...valuen}访问结构成员
要访问结构的任何成员，我们使用成员访问运算符(.)。成员访问运算符被编码为结构变量名和我们希望访问的结构成员之间的句点。你会用struct关键字来定义结构类型的变量。以下示例说明了如何使用结构：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
fmt.Printf( "Book 1 title : %s\n", Book1.title)
fmt.Printf( "Book 1 author : %s\n", Book1.author)
fmt.Printf( "Book 1 subject : %s\n", Book1.subject)
fmt.Printf( "Book 1 book_id : %d\n", Book1.book_id)
/* print Book2 info */
fmt.Printf( "Book 2 title : %s\n", Book2.title)
fmt.Printf( "Book 2 author : %s\n", Book2.author)
fmt.Printf( "Book 2 subject : %s\n", Book2.subject)
fmt.Printf( "Book 2 book_id : %d\n", Book2.book_id)
}编译并执行上述代码后，将产生以下结果：
Book 1 title : Go Programming Book 1 author : Mahesh Kumar Book 1 subject : Go Programming Tutorial Book 1 book_id : 6495407 Book 2 title : Telecom Billing Book 2 author : Zara Ali Book 2 subject : Telecom Billing Tutorial Book 2 book_id : 6495700
结构作为函数参数
你可以通过与传递任何其他变量或指针非常相似的方式将结构作为函数参数传递。你将以与上述示例相同的方式访问结构变量：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
printBook(Book1)
/* print Book2 info */
printBook(Book2)
}
func printBook( book Books ) {
fmt.Printf( "Book title : %s\n", book.title);
fmt.Printf( "Book author : %s\n", book.author);
fmt.Printf( "Book subject : %s\n", book.subject);
fmt.Printf( "Book book_id : %d\n", book.book_id);
}编译并执行上述代码后，将产生以下结果：
Book title : Go Programming Book author : Mahesh Kumar Book subject : Go Programming Tutorial Book book_id : 6495407 Book title : Telecom Billing Book author : Zara Ali Book subject : Telecom Billing Tutorial Book book_id : 6495700
指向结构的指针
你可以使用与定义任何其他变量的指针相同的方式来定义指向结构的指针，如下所示：
var struct_pointer *Books
现在，你可以将结构变量的地址存储在上面定义的指针变量中。要查找结构变量的地址，请在结构名称之前放置＆运算符，如下所示：
struct_pointer = &Book1;
要使用指向该结构的指针访问该结构的成员，必须使用“。”。运算符如下：
struct_pointer.title;
让我们使用结构指针重新编写以上示例：
package main
import "fmt"
type Books struct {
title string
author string
subject string
book_id int
}
func main() {
var Book1 Books /* Declare Book1 of type Book */
var Book2 Books /* Declare Book2 of type Book */
/* book 1 specification */
Book1.title = "Go Programming"
Book1.author = "Mahesh Kumar"
Book1.subject = "Go Programming Tutorial"
Book1.book_id = 6495407
/* book 2 specification */
Book2.title = "Telecom Billing"
Book2.author = "Zara Ali"
Book2.subject = "Telecom Billing Tutorial"
Book2.book_id = 6495700
/* print Book1 info */
printBook(&Book1)
/* print Book2 info */
printBook(&Book2)
}
func printBook( book *Books ) {
fmt.Printf( "Book title : %s\n", book.title);
fmt.Printf( "Book author : %s\n", book.author);
fmt.Printf( "Book subject : %s\n", book.subject);
fmt.Printf( "Book book_id : %d\n", book.book_id);
}编译并执行上述代码后，将产生以下结果：
Book title : Go Programming Book author : Mahesh Kumar Book subject : Go Programming Tutorial Book book_id : 6495407 Book title : Telecom Billing Book author : Zara Ali Book subject : Telecom Billing Tutorial Book book_id : 6495700