Go數(shù)組允許定義一種可以保存多個相同類型的數(shù)據(jù)項(xiàng)的變量類型，但結(jié)構(gòu)體是Go編程中可用的另一個用戶定義的數(shù)據(jù)類型，它允許組合不同類型的數(shù)據(jù)項(xiàng)。

結(jié)構(gòu)體用于表示記錄，假設(shè)想在圖書館中跟蹤圖書?？赡芟Ｍ櫭勘緢D書的以下屬性：

• 標(biāo)題(Title)
• 作者(Author)
• 科目(Subject)
• 圖書編號(Book ID)

定義結(jié)構(gòu)體

要定義結(jié)構(gòu)，必須使用type和struct語句。struct語句定義了一個新的數(shù)據(jù)類型，在程序中有多個成員。type語句在例子中綁定一個類型為struct的名字。 struct語句的格式如下：

type struct_variable_type struct {
   member definition;
   member definition;
   ...
   member definition;
}

當(dāng)定義了結(jié)構(gòu)體類型，它可以用于使用以下語法聲明該類型的變量。

variable_name := structure_variable_type {value1, value2...valuen}

訪問結(jié)構(gòu)體成員

要訪問結(jié)構(gòu)的任何成員，可使用成員訪問運(yùn)算符(.)。成員訪問運(yùn)算符被編碼為結(jié)構(gòu)變量名稱和希望訪問的結(jié)構(gòu)成員的名稱。使用struct關(guān)鍵字定義結(jié)構(gòu)類型的變量。以下是解釋結(jié)構(gòu)用法的示例：

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 */
   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)
}

當(dāng)上述代碼編譯和執(zhí)行時，它產(chǎn)生以下結(jié)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

結(jié)構(gòu)體作為函數(shù)參數(shù)

可以傳遞一個結(jié)構(gòu)體作為一個函數(shù)參數(shù)，與傳遞其他變量或指針的方式非常相似。可以使用類似于上面示例中訪問的方式來訪問結(jié)構(gòu)變量：

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);
}

當(dāng)上述代碼編譯和執(zhí)行時，它產(chǎn)生以下結(jié)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

指針指向結(jié)構(gòu)

可以以非常類似于定義指向其他變量的指針的方式來定義結(jié)構(gòu)的指針，如下所示：

var struct_pointer *Books

現(xiàn)在，可以在上面定義的指針變量中存儲結(jié)構(gòu)體變量的地址。要查找結(jié)構(gòu)體變量的地址，將&操作符放在結(jié)構(gòu)體名稱之前，如下：

struct_pointer = &Book1;

要使用指向該結(jié)構(gòu)體的指針來訪問結(jié)構(gòu)的成員，必須使用“.”。 運(yùn)算符如下：

struct_pointer.title;

現(xiàn)在，重寫上面的例子使用結(jié)構(gòu)指針，希望這能讓您更容易地理解這個概念，代碼如下：

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);
}

當(dāng)上述代碼編譯和執(zhí)行時，它產(chǎn)生以下結(jié)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