Tuple<T1,T2,T3>.Item1 属性

定义

获取当前 Tuple<T1,T2,T3> 对象的第一个分量的值。Gets the value of the current Tuple<T1,T2,T3> object's first component.

public:
 property T1 Item1 { T1 get(); };
public T1 Item1 { get; }
member this.Item1 : 'T1
Public ReadOnly Property Item1 As T1

属性值

T1

当前 Tuple<T1,T2,T3> 对象的第一个分量的值。The value of the current Tuple<T1,T2,T3> object's first component.

示例

下面的示例定义了一个Tuple<T1,T2,T3>对象的数组, 这些对象包含学生姓名、平均测验成绩和所进行的测试数。The following example defines an array of Tuple<T1,T2,T3> objects that contain the names of students, their average test scores, and the number of tests taken. 将数组传递给ComputeStatistics方法, 该方法计算平均分数、标准偏差和计算统计信息的事例数。The array is passed to the ComputeStatistics method, which calculates the mean score, standard deviation, and number of cases from which the statistics are calculated. 这些值存储在Tuple<T1,T2,T3> ComputeStatistics由方法返回的对象中。These values are stored in the Tuple<T1,T2,T3> object that is returned by the ComputeStatistics method. Item1属性包含事例数。The Item1 property contains the number of cases.

using System;

public class Example
{
   public static void Main()
   {
      Tuple<string, double, int>[] scores = 
                    { Tuple.Create("Jack", 78.8, 8),
                      Tuple.Create("Abbey", 92.1, 9), 
                      Tuple.Create("Dave", 88.3, 9),
                      Tuple.Create("Sam", 91.7, 8), 
                      Tuple.Create("Ed", 71.2, 5),
                      Tuple.Create("Penelope", 82.9, 8),
                      Tuple.Create("Linda", 99.0, 9),
                      Tuple.Create("Judith", 84.3, 9) };
      var result = ComputeStatistics(scores);
      Console.WriteLine("Mean score: {0:N2} (SD={1:N2}) (n={2})", 
                        result.Item2, result.Item3, result.Item1);
   }

   private static Tuple<int, double, double> ComputeStatistics(Tuple<string, double, int>[] scores) 
   {
      int n = 0;
      double sum = 0;

      // Compute the mean.
      foreach (var score in scores)
      {
         n += score.Item3;
         sum += score.Item2 * score.Item3;
      }
      double mean = sum / n;
      
      // Compute the standard deviation.
      double ss = 0;
      foreach (var score in scores)
      {
         ss = Math.Pow(score.Item2 - mean, 2);
      }
      double sd = Math.Sqrt(ss/scores.Length);
      return Tuple.Create(scores.Length, mean, sd);
   }
}
// The example displays the following output:
//       Mean score: 87.02 (SD=0.96) (n=8)
Module Example
   Public Sub Main()
      Dim scores() = 
                      { Tuple.Create("Jack", 78.8, 8),
                        Tuple.Create("Abbey", 92.1, 9), 
                        Tuple.Create("Dave", 88.3, 9),
                        Tuple.Create("Sam", 91.7, 8), 
                        Tuple.Create("Ed", 71.2, 5),
                        Tuple.Create("Penelope", 82.9, 8),
                        Tuple.Create("Linda", 99.0, 9),
                        Tuple.Create("Judith", 84.3, 9) }
      Dim result = ComputeStatistics(scores)
      Console.WriteLine("Mean score: {0:N2} (SD={1:N2}) (n={2})", 
                        result.Item2, result.Item3, result.Item1)
   End Sub
   
   Private Function ComputeStatistics(scores() As Tuple(Of String, Double, Integer)) _ 
                                As Tuple(Of Integer, Double, Double)
      Dim n As Integer = 0      
      Dim sum As Double = 0
      
      ' Compute the mean.
      For Each score In scores
         n+= score.Item3 
         sum += score.Item2 * score.Item3
      Next     
      Dim mean As Double = sum / n

      ' Compute the standard deviation.
      Dim ss As Double = 0
      For Each score In scores
         ss = Math.Pow(score.Item2 - mean, 2)
      Next
      Dim sd As Double = Math.Sqrt(ss/scores.Length)
      Return Tuple.Create(scores.Length, mean, sd)
   End Function
End Module
' The example displays the following output:
'       Mean score: 87.02 (SD=0.96) (n=8)

注解

可以通过以下两种方式之一动态Item1确定组件的类型:You can dynamically determine the type of the Item1 component in one of two ways:

适用于