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C# Tutorial
author:php.cn  update time:2022-04-11 14:06:23

C# Structure (Struct)



In C#, a structure is a value type data structure. It allows a single variable to store related data of various data types. struct keyword is used to create structures.

The structure is used to represent a record. Suppose you want to track the movement of books in your library. You may want to track the following properties for each book:

  • Title

  • Author

  • Subject

  • Book ID

Defining Structure

In order to define a structure, you must use the struct statement. The struct statement defines a new data type with multiple members for the program.

For example, you can declare the Book structure as follows:

struct Books
{
   public string title;
   public string author;
   public string subject;
   public int book_id;
};

The following program demonstrates the use of the structure:

using System;
     
struct Books
{
   public string title;
   public string author;
   public string subject;
   public int book_id;
};  

public class testStructure
{
   public static void Main(string[] args)
   {

      Books Book1;        /* 声明 Book1,类型为 Book */
      Books Book2;        /* 声明 Book2,类型为 Book */

      /* book 1 详述 */
      Book1.title = "C Programming";
      Book1.author = "Nuha Ali"; 
      Book1.subject = "C Programming Tutorial";
      Book1.book_id = 6495407;

      /* book 2 详述 */
      Book2.title = "Telecom Billing";
      Book2.author = "Zara Ali";
      Book2.subject =  "Telecom Billing Tutorial";
      Book2.book_id = 6495700;

      /* 打印 Book1 信息 */
      Console.WriteLine( "Book 1 title : {0}", Book1.title);
      Console.WriteLine("Book 1 author : {0}", Book1.author);
      Console.WriteLine("Book 1 subject : {0}", Book1.subject);
      Console.WriteLine("Book 1 book_id :{0}", Book1.book_id);

      /* 打印 Book2 信息 */
      Console.WriteLine("Book 2 title : {0}", Book2.title);
      Console.WriteLine("Book 2 author : {0}", Book2.author);
      Console.WriteLine("Book 2 subject : {0}", Book2.subject);
      Console.WriteLine("Book 2 book_id : {0}", Book2.book_id);       

      Console.ReadKey();

   }
}

When the above code is compiled and executed , which produces the following results:

Book 1 title : C Programming
Book 1 author : Nuha Ali
Book 1 subject : C 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

C# Structure Features

You have used a simple structure called Books. Structures in C# are different from structures in traditional C or C++. Structures in C# have the following characteristics:

  • Structures can have methods, fields, indexes, properties, operator methods and events.

  • Structures can define constructors, but not destructors. However, you cannot define a default constructor for a structure. The default constructor is automatically defined and cannot be changed.

  • Unlike classes, structures cannot inherit other structures or classes.

  • Structures cannot serve as the base structure for other structures or classes.

  • The structure can implement one or more interfaces.

  • Structure members cannot be specified as abstract, virtual, or protected.

  • When you create a structure object using the New operator, the appropriate constructor is called to create the structure. Unlike classes, structures can be instantiated without using the New operator.

  • If you do not use the New operator, the fields are assigned and the object is used only after all fields are initialized.

Class vs structure

Classes and structures have the following basic differences:

  • Classes are reference types, Structures are value types.

  • Structure does not support inheritance.

  • Structures cannot declare a default constructor.

In response to the above discussion, let us rewrite the previous example:

using System;
     
struct Books
{
   private string title;
   private string author;
   private string subject;
   private int book_id;
   public void getValues(string t, string a, string s, int id)
   {
      title = t;
      author = a;
      subject = s;
      book_id = id;
   }
   public void display()
   {
      Console.WriteLine("Title : {0}", title);
      Console.WriteLine("Author : {0}", author);
      Console.WriteLine("Subject : {0}", subject);
      Console.WriteLine("Book_id :{0}", book_id);
   }

};  

public class testStructure
{
   public static void Main(string[] args)
   {

      Books Book1 = new Books(); /* 声明 Book1,类型为 Book */
      Books Book2 = new Books(); /* 声明 Book2,类型为 Book */

      /* book 1 详述 */
      Book1.getValues("C Programming",
      "Nuha Ali", "C Programming Tutorial",6495407);

      /* book 2 详述 */
      Book2.getValues("Telecom Billing",
      "Zara Ali", "Telecom Billing Tutorial", 6495700);

      /* 打印 Book1 信息 */
      Book1.display();

      /* 打印 Book2 信息 */
      Book2.display(); 

      Console.ReadKey();

   }
}

When the above code is compiled and executed, it will produce the following results:

Title : C Programming
Author : Nuha Ali
Subject : C Programming Tutorial
Book_id : 6495407
Title : Telecom Billing
Author : Zara Ali
Subject : Telecom Billing Tutorial
Book_id : 6495700

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