元组是一种数据结构，它为您提供了一种表示具有多个可能(可能不相关)的值的数据集的最简单方法。但是，如果您尝试从元组中检索多个字段或属性值，则更加困难。因此，为克服此问题，在C＃7.0中引入了析构函数。它用于将变量值或元组划分为多个部分，并将这些值分配给新变量。它也与类和结构一起使用。在这里，我们仅讨论使用元组进行解构的工作。
在元组中，使用解构函数将元组划分为多个部分，并将这些部分分别分配给新变量。因此，您可以访问单个字段或属性值。您可以通过四种不同的方式来构造一个元组：
1.您可以通过在括号内显式声明每个字段的类型来解构元组。但是，即使元组中的每个字段都是同一类型，也不允许在括号外指定特定类型。如果尝试这样做，则会出现错误。
例子：
// C# program to illustrate the concept
// of deconstruction with the tuple
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp1 {
class GFG {
// This method returns the Pet details
public(string, string, int, int, string) PetDetails(string type,
string name, int height, int age, string color)
{
string p_type = type;
string p_name = name;
int p_height = height;
int p_age = age;
string p_color = color;
return (p_type, p_name, p_height, p_height, p_color);
}
// Main method
static void Main(string[] args)
{
// Creating object of GFG class
GFG g = new GFG();
// Deconstruct the given tuple
// So that we can directly access individual fields
// By explicitly declaring types
(string type, string name, int height, int age, string color) = g.PetDetails("Dog",
"Dollar", 124, 3, "White");
Console.WriteLine("Pet Details:");
Console.WriteLine("Type: " + type);
Console.WriteLine("Name: " + name);
Console.WriteLine("Height: " + height);
Console.WriteLine("Age: " + age);
Console.WriteLine("Color: " + color);
Console.ReadLine();
}
}
}
输出：
2.您可以使用var关键字解构元组，以便C＃推断每个变量的类型。您可以通过两种不同的方式使用var关键字：
- 您可以将var关键字放在括号之外。
- 您可以将var关键字分别放在带有某些或所有变量的括号内。
例子：
// C# program to illustrate the concept
// of deconstruction with the tuple
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp1 {
class GFG {
// This method returns the Pet details
public(string, string, int, int, string) PetDetails(string type,
string name, int height, int age, string color)
{
string p_type = type;
string p_name = name;
int p_height = height;
int p_age = age;
string p_color = color;
return (p_type, p_name, p_height, p_height, p_color);
}
// Main method
static void Main(string[] args)
{
// Creating object of GFG class
GFG g = new GFG();
// Deconstruct the given tuple
// So that we can directly
// access individual fields
// Using var keyword
var(type1, name1, height1, age1, color1) = g.PetDetails("Dog",
"Dollar", 124, 3, "White");
Console.WriteLine("Pet Details:");
Console.WriteLine("Type: " + type1);
Console.WriteLine("Name: " + name1);
Console.WriteLine("Height: " + height1);
Console.WriteLine("Age: " + age1);
Console.WriteLine("Color: " + color1);
(var type2, var name2, var height2, var age2, var color2) = g.PetDetails("Cat",
"Poo", 104, 1, "Black&White");
Console.WriteLine("\nPet Details:");
Console.WriteLine("Type: " + type2);
Console.WriteLine("Name: " + name2);
Console.WriteLine("Height: " + height2);
Console.WriteLine("Age: " + age2);
Console.WriteLine("Color: " + color2);
Console.ReadLine();
}
}
}
输出：
3.您可以将元组解构为已声明的变量。如下例所示：
例子：
// C# program to illustrate the concept
// of deconstruction with the tuple
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp1 {
class GFG {
// This method returns the Pet details
public(string, string, int, int, string) PetDetails(string type,
string name, int height, int age, string color)
{
string p_type = type;
string p_name = name;
int p_height = height;
int p_age = age;
string p_color = color;
return (p_type, p_name, p_height, p_height, p_color);
}
// Main method
static void Main(string[] args)
{
// Creating object of GFG class
GFG g = new GFG();
// Declaring and initializing variables
string type = "Cow";
string name = "BooBoo";
int height = 234;
int age = 4;
string color = "Black&white";
// Deconstruct the given tuple
// So that we can directly
// access individual fields
// By declaring variables
(type, name, height, age, color) = g.PetDetails("Cat",
"Mew", 105, 2, "Brown");
Console.WriteLine("Pet Details:");
Console.WriteLine("Type: " + type);
Console.WriteLine("Name: " + name);
Console.WriteLine("Height: " + height);
Console.WriteLine("Age: " + age);
Console.WriteLine("Color: " + color);
Console.ReadLine();
}
}
}
输出：
4.您也可以在解构中使用丢弃物。丢弃是只写变量，其值应被忽略。并且在分配中使用下划线字符(“ _”)来指定丢弃。您可以根据需要舍弃任意多个值，并且所有值都由单个舍弃_表示。
句法：
(var1, _, var3, _, var5) = method_name(var1_values, var2_values, var3_value, var4_values, var5_value);
例子：
// C# program to illustrate the concept
// of deconstruction with tuple
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace ConsoleApp1 {
class GFG {
// This method returns
// the Pet details
public(string, string, int, int, string) PetDetails(string type,
string name, int height, int age, string color)
{
string p_type = type;
string p_name = name;
int p_height = height;
int p_age = age;
string p_color = color;
return (p_type, p_name, p_height, p_height, p_color);
}
// Main method
static void Main(string[] args)
{
// Creating object of GFG class
GFG g = new GFG();
// Discarding field values
// in deconstruction
(string type, _, int height, _, string color) = g.PetDetails("Dog",
"Dollar", 124, 3, "White");
Console.WriteLine("Pet Details:");
Console.WriteLine("Type: " + type);
Console.WriteLine("Height: " + height);
Console.WriteLine("Color: " + color);
Console.ReadLine();
}
}
}
输出：
注意：在解构中，如果要消除任何元素，则需要将每个元素分配给一个变量，然后编译器将给出错误信息。而且，如果您消除了任何元素，则不允许在解构的左侧混合对现有变量的声明和赋值，否则编译器将给出错误消息。