C# |带有元组的解构器
元组是一种数据结构，它为您提供了最简单的方式来表示具有多个值的数据集，这些值可能彼此相关，也可能彼此不相关。但是如果您试图从元组中检索多个字段或属性值就比较困难了。所以，为了克服这个问题，解构器在 C# 7.0 中被引入。它用于将变量值或元组分成多个部分，并将这些值分配给新变量。它也用于类和结构。这里我们只讨论解构器对元组的处理。
在元组中，解构器用于将元组分成多个部分，并将这些部分分别分配到新的变量中。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 解构一个元组:
1。您可以通过显式声明括号内每个字段的类型来解构元组。但是不允许在括号外指定特定的类型，即使元组中的每个字段都是相同的类型。如果你试图这样做，那么你会得到一个错误。
示例:
// 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。可以使用 var 关键字解构元组，这样 C# 就可以推断出每个变量的类型。您可以通过两种不同的方式使用 var 关键字:
- 您可以将 var 关键字放在括号外。
- 您可以将 var 关键字单独放在带有部分或全部变量的括号内。
示例:
// 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经声明的变量。如下例所示:
示例:
// 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。你也可以在解构中使用丢弃。丢弃是只写变量，其值应该被忽略。和丢弃是通过在赋值中使用下划线字符(“_”)来指定的。您可以根据需要丢弃任意多个值，所有值都由单个丢弃表示。
语法:
(var1，，var3，，var5) = method_name(var1_values，var2_values，var3_value，var4_values，var5 _ value)；
示例:
// 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，需要将每个元素赋给一个变量，如果去掉任何一个元素，那么编译器就会给出一个错误。不允许将声明和赋值混合到解构左侧的现有变量中。如果您删除任何元素，编译器会给出一个错误。
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