ValueTuple是C#7.0中引入的结构,表示值类型Tuple。它允许您存储一个数据集,该数据集包含可能彼此相关或不相关的多个值。 Item2属性用于获取给定值元组的第二个未命名元素。它适用于每个值元组,例如2-ValueTuple,3-ValueTuple等。
句法:
public T2 Item2;
在此,T2是ValueTuple <>结构的字段值。此ValueTuple <>可以是2-ValueTuple或3-ValueTuple或4-ValueTuple或5-ValueTuple或6-ValueTuple或7-ValueTuple或8-ValueTuple。
示例:在下面的代码中,您可以看到我们正在访问每个值元组的第二个元素。
// C# program to illustrate how to get
// the second element of value tuple
using System;
class GFG {
// Main Method
static public void Main()
{
Console.WriteLine("C# Topics:");
// Creating a value tuple
// with two elements
var ValTpl2 = ValueTuple.Create("Array",
"String");
// Accessing the second element of
// 2-ValueTuple using Item property
Console.WriteLine(ValTpl2.Item2);
// Creating a value tuple
// with three elements
var ValTpl3 = ValueTuple.Create("ArrayList",
"List", "Queue");
// Accessing the second element of
// 3-ValueTuple using Item property
Console.WriteLine(ValTpl3.Item2);
// Creating a value tuple
// with four elements
var ValTpl4 = ValueTuple.Create("Stack", "Dictionary",
"LinkedList", "Interface");
// Accessing the second element of
// 4-ValueTuple using Item property
Console.WriteLine(ValTpl4.Item2);
// Creating a value tuple with five elements
var ValTpl5 = ValueTuple.Create("Identifiers", "Data Types",
"Keywords", "Access Modifiers", "Operators");
// Accessing the second element of
// 5-ValueTuple using Item property
Console.WriteLine(ValTpl5.Item2);
// Creating a value tuple with six elements
var ValTpl6 = ValueTuple.Create("Nullable Types", "Class",
"Structure", "Indexers", "Switch Statement", "Loops");
// Accessing the second element of
// 6-ValueTuple using Item property
Console.WriteLine(ValTpl6.Item2);
// Creating a value tuple with seven elements
var ValTpl7 = ValueTuple.Create("Inheritance ", "Constructors",
"Encapsulation", "Abstraction", "Static Class",
"Partial Classes", "this keyword");
// Accessing the second element of
// 7-ValueTuple using Item property
Console.WriteLine(ValTpl7.Item2);
// Creating a value tuple with eight elements
var ValTpl8 = ValueTuple.Create("Methods", "Method Hiding",
"Optional Parameters", "Anonymous Method",
"Partial Methods", "Local Function", "Delegates",
"Destructors");
// Accessing the second element of
// 8-ValueTuple using Item property
Console.WriteLine(ValTpl8.Item2);
}
}
输出:
C# Topics:
String
List
Dictionary
Data Types
Class
Constructors
Method Hiding