Tuple<T1,T2,T3>.Item2 Properti

Definisi

Ruang nama:

System

Rakitan:

netstandard.dll, System.Runtime.dll

Sumber:

Tuple.cs

Mendapatkan nilai komponen kedua objek saat ini Tuple<T1,T2,T3> .

public:
 property T2 Item2 { T2 get(); };

public T2 Item2 { get; }

member this.Item2 : 'T2

Public ReadOnly Property Item2 As T2

Nilai Properti

T2

Nilai komponen kedua objek saat ini Tuple<T1,T2,T3> .

Contoh

Contoh berikut mendefinisikan array Tuple<T1,T2,T3> objek yang berisi nama siswa, skor pengujian rata-rata mereka, dan jumlah pengujian yang diambil. Array diteruskan ke ComputeStatistics metode , yang menghitung skor rata-rata, simpangihan standar, dan jumlah kasus tempat statistik dihitung. Nilai-nilai ini disimpan dalam Tuple<T1,T2,T3> objek yang dikembalikan oleh ComputeStatistics metode . Properti Item2 berisi skor pengujian rata-rata.

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)

open System

let computeStatistics (scores: Tuple<string, double, int>[]) = 
    let mutable n = 0
    let mutable sum = 0.

    // Compute the mean.
    for score in scores do
        n <- n + score.Item3
        sum <- sum + score.Item2 * double score.Item3
    let mean = sum / double n
    
    // Compute the standard deviation.
    let mutable ss = 0.
    for score in scores do
        ss <- (score.Item2 - mean) ** 2.
    let sd = sqrt (ss / double scores.Length)
    Tuple.Create(scores.Length, mean, sd)

let 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) |]
let result = computeStatistics scores
printfn $"Mean score: {result.Item2:N2} (SD={result.Item3:N2}) (n={result.Item1})"
// 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)

Keterangan

Anda dapat menentukan jenis Item2 komponen secara dinamis dengan salah satu dari dua cara:

• Dengan memanggil GetType metode pada nilai yang dikembalikan oleh Item2 properti .

• Dengan mengambil Type objek yang mewakili Tuple<T1,T2,T3> objek, dan mengambil elemen kedua dari array yang dikembalikan oleh metodenya Type.GetGenericArguments .