Tuple<T1,T2>.IComparable.CompareTo(Object) Method

 virtual int System.IComparable.CompareTo(System::Object ^ obj) = IComparable::CompareTo;

int IComparable.CompareTo (object obj);

abstract member System.IComparable.CompareTo : obj -> int
override this.System.IComparable.CompareTo : obj -> int

Function CompareTo (obj As Object) As Integer Implements IComparable.CompareTo

Parameters

Returns

A signed integer that indicates the relative position of this instance and obj in the sort order, as shown in the following table.

Implements

Exceptions

Examples

The following example creates an array of Tuple<T1,T2> objects that consist of a student's name and test score. It displays the component of each tuple in the array in unsorted order, sorts the array, and then calls ToString to display the value of each tuple in sorted order. The output shows that the array has been sorted by its first component. Note that the example does not directly call the IComparable.CompareTo(Object) method. This method is called implicitly by the Sort(Array) method for each element in the array.

using System;

public class Example
{
   public static void Main()
   {
      Tuple<string, Nullable<int>>[] scores = 
                    { new Tuple<string, Nullable<int>>("Jack", 78),
                      new Tuple<string, Nullable<int>>("Abbey", 92), 
                      new Tuple<string, Nullable<int>>("Dave", 88),
                      new Tuple<string, Nullable<int>>("Sam", 91), 
                      new Tuple<string, Nullable<int>>("Ed", null),
                      new Tuple<string, Nullable<int>>("Penelope", 82),
                      new Tuple<string, Nullable<int>>("Linda", 99),
                      new Tuple<string, Nullable<int>>("Judith", 84) };

      Console.WriteLine("The values in unsorted order:");
      foreach (Tuple<string, Nullable<int>> score in scores)
         Console.WriteLine(score.ToString());

      Console.WriteLine();

      Array.Sort(scores);

      Console.WriteLine("The values in sorted order:");
      foreach (Tuple<string, Nullable<int>> score in scores)
         Console.WriteLine(score.ToString());
   }
}
// The example displays the following output;
//       The values in unsorted order:
//       (Jack, 78)
//       (Abbey, 92)
//       (Dave, 88)
//       (Sam, 91)
//       (Ed, )
//       (Penelope, 82)
//       (Linda, 99)
//       (Judith, 84)
//       
//       The values in sorted order:
//       (Abbey, 92)
//       (Dave, 88)
//       (Ed, )
//       (Jack, 78)
//       (Judith, 84)
//       (Linda, 99)
//       (Penelope, 82)
//       (Sam, 91)

open System

let scores = 
    [| Tuple<string, Nullable<int>>("Jack", 78)
       Tuple<string, Nullable<int>>("Abbey", 92) 
       Tuple<string, Nullable<int>>("Dave", 88)
       Tuple<string, Nullable<int>>("Sam", 91) 
       Tuple<string, Nullable<int>>("Ed", Nullable())
       Tuple<string, Nullable<int>>("Penelope", 82)
       Tuple<string, Nullable<int>>("Linda", 99)
       Tuple<string, Nullable<int>>("Judith", 84) |]

printfn "The values in unsorted order:"
for score in scores do
    printfn $"{score}"

printfn ""

Array.Sort scores

printfn "The values in sorted order:"
for score in scores do
    printfn $"{score}"
// The example displays the following output
//       The values in unsorted order:
//       (Jack, 78)
//       (Abbey, 92)
//       (Dave, 88)
//       (Sam, 91)
//       (Ed, )
//       (Penelope, 82)
//       (Linda, 99)
//       (Judith, 84)
//       
//       The values in sorted order:
//       (Abbey, 92)
//       (Dave, 88)
//       (Ed, )
//       (Jack, 78)
//       (Judith, 84)
//       (Linda, 99)
//       (Penelope, 82)
//       (Sam, 91)

Module Example
   Public Sub Main()
      Dim scores() As Tuple(Of String, Nullable(Of Integer)) = 
                      { New Tuple(Of String, Nullable(Of Integer))("Jack", 78),
                        New Tuple(Of String, Nullable(Of Integer))("Abbey", 92), 
                        New Tuple(Of String, Nullable(Of Integer))("Dave", 88),
                        New Tuple(Of String, Nullable(Of Integer))("Sam", 91), 
                        New Tuple(Of String, Nullable(Of Integer))("Ed", Nothing),
                        New Tuple(Of String, Nullable(Of Integer))("Penelope", 82),
                        New Tuple(Of String, Nullable(Of Integer))("Linda", 99),
                        New Tuple(Of String, Nullable(Of Integer))("Judith", 84) }

      Console.WriteLine("The values in unsorted order:")
      For Each score In scores
         Console.WriteLine(score.ToString())
      Next
      Console.WriteLine()

      Array.Sort(scores)

      Console.WriteLine("The values in sorted order:")
      For Each score In scores
         Console.WriteLine(score.ToString())
      Next
   End Sub
End Module
' The example displays the following output;
'       The values in unsorted order:
'       (Jack, 78)
'       (Abbey, 92)
'       (Dave, 88)
'       (Sam, 91)
'       (Ed, )
'       (Penelope, 82)
'       (Linda, 99)
'       (Judith, 84)
'       
'       The values in sorted order:
'       (Abbey, 92)
'       (Dave, 88)
'       (Ed, )
'       (Jack, 78)
'       (Judith, 84)
'       (Linda, 99)
'       (Penelope, 82)
'       (Sam, 91)

Remarks

This member is an explicit interface member implementation. It can be used only when the Tuple<T1,T2> instance is cast to an IComparable interface.

This method provides the IComparable.CompareTo implementation for the Tuple<T1,T2> class. Although the method can be called directly, it is most commonly called by the default overloads of collection sorting methods, such as Array.Sort(Array) and SortedList.Add, to order the members of a collection.

The Tuple<T1,T2>.IComparable.CompareTo method uses the default object comparer to compare each component.

Applies to

See also

• Equals(Object)