c# ValueTuple

为什么我们需要 ValueTuple？

Tuple 是引用类型，但 ValueTuple 是值类型。Tuple 不提供命名约定，但 ValueTuple 提供了强大的命名约定。在 Tuples 中，您不能创建零分量的元组，但在 ValueTuple 中，您可以创建零元素的元组。ValueTuple 的性能优于 Tuple。 因为 ValueTuple 提供了一种轻量级的机制，用于从现有方法返回多个值。 并且 ValueTuple 的语法比 Tuples 更优化。ValueTuple 通过使用解构和 _ 关键字为访问值元组的元素提供了更大的灵活性。 但是 Tuple 不能提供解构的概念和 _ 关键字。在 ValueTuple 中，item1 和 item2 等成员是字段。 但在元组中，它们是属性。在 ValueTuple 中，字段是可变的。 但是在元组中，字段是只读的。

Creating a ValueTuple

Using Constructor

// Constructor for creating one element
ValueTuple(T1)
// Constructor for creating two elements
ValueTuple<T1, T2>(T1, T2)
// Constructor for creating eight elements
ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>(T1, T2, T3, T4, T5, T6, T7, TRest) /

Sample

using System; class GFG {     // Main method    static public void Main()    {         // ValueTuple with one element        ValueTuple<int> ValTpl1 = new ValueTuple<int>(345678);         // ValueTuple with three elements        ValueTuple<string, string, int> ValTpl2 = new ValueTuple<string,                                        string, int>("C#", "Java", 586);         // ValueTuple with eight elements        ValueTuple<int, int, int, int, int, int, int, ValueTuple<int> > ValTpl3 = new ValueTuple<int,                                  int, int, int, int, int, int, ValueTuple<int> >(45, 67, 65, 34, 34,                                                                    34, 23, new ValueTuple<int>(90));    }}

Using Create Method

// Method for creating an empty value tuple
Create();
// Method for creating 1-ValueTuple
Create(T1)
// Method for creating 8-ValueTuple
Create<T1, T2, T3, T4, T5, T6, T7, TRest>(T1, T2, T3, T4, T5, T6, T7, T8)

Sample

using System; public class GFG {     // Main method    static public void Main()    {         // Creating 0-ValueTuple        // Using Create() Method        var Valtpl1 = ValueTuple.Create();         // Creating 3-ValueTuple        // Using Create(T1, T2, T3) Method        var Valtpl2 = ValueTuple.Create(12, 30, 40, 50);         // Creating 8-ValueTuple        // Using Create(T1, T2, T3, T4, T5, T6, T7, T8) Method        var Valtpl3 = ValueTuple.Create(34, "GeeksforGeeks",                      'g', 'f', 'g', 56.78, 4323, "geeks");    }}

Using parenthesis()

named member

using System; public class GFG {    static public void Main()    {        (int age, string Aname, string Lang) author = (23, "Sonia", "C#");    }}

using System; public class GFG {     static public void Main()    {        var author = (age : 23, Aname                      : "Sonia", Lang                      : "C#");    }}

UnNamed Member

using System; public class GFG {    static public void Main()    {        var author = (20, "Siya", "Ruby");    }}

using System; public class GFG {    static public void Main()    {        ValueTuple<int, string, string> author = (20, "Siya", "Ruby");    }}

Accessing ValueTuple members

Accessing unnamed members

using System; public class GFG {     // Main Method    static public void Main()    {         // ValueTuple with three elements        var author = (20, "Siya", "Ruby");         // Accessing the ValueTuple        // Using default Item property        Console.WriteLine("Age:" + author.Item1);        Console.WriteLine("Name:" + author.Item2);        Console.WriteLine("Language:" + author.Item3);    }}

Accessing Named members:

using System; public class GFG {     // Main Method    static public void Main()    {         // ValueTuple with three elements        var library = (Book_id : 2340, Author_name                       : "Arundhati Roy", Book_name                       : "The God of Small Things");         // Accessing the ValueTuple        // according to their names        Console.WriteLine("Book Id: {0}", library.Book_id);        Console.WriteLine("Author Name: {0}", library.Author_name);        Console.WriteLine("Book Name: {0}", library.Book_name);    }}

Returning ValueTuple

using System; public class GFG {     // This method returns the tourist details    static(int, string, string) TouristDetails()    {        return (384645, "Sophite", "USA");    }     // Main method    static public void Main()    {         // Store the data provided by the TouristDetails method        var(Tourist_Id, Tourist_Name, Country) = TouristDetails();         // Display data        Console.WriteLine("Tourist Details: ");        Console.WriteLine($ "Tourist Id: {Tourist_Id}");        Console.WriteLine($ "Tourist Name: {Tourist_Name}");        Console.WriteLine($ "Country: {Country}");    }}