Tuple<T1, T2, T3>.IComparable.CompareTo Method (Object)


Compares the current Tuple<T1, T2, T3> object to a specified object and returns an integer that indicates whether the current object is before, after, or in the same position as the specified object in the sort order.

Namespace:   System
Assembly:  mscorlib (in mscorlib.dll)

int IComparable.CompareTo(
	object obj


Type: System.Object

An object to compare with the current instance.

Return Value

Type: System.Int32

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



A negative integer

This instance precedes obj.


This instance and obj have the same position in the sort order.

A positive integer

This instance follows obj.

Exception Condition

obj is not a Tuple<T1, T2, T3> object.

This member is an explicit interface member implementation. It can be used only when the Tuple<T1, T2, T3> instance is cast to an IComparable interface.

This method provides the IComparable.CompareTo implementation for the Tuple<T1, T2, T3> 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, T3>.IComparable.CompareTo method is intended for use in sorting operations. It should not be used when the primary purpose of a comparison is to determine whether two objects are equal. To determine whether two objects are equal, call the Equals method.

The Tuple<T1, T2, T3>.IComparable.CompareTo method uses the default object comparer to compare each component.

The following example creates an array of Tuple<T1, T2, T3> objects whose components consist of a student's name, mean test score, and number of tests. It displays the components of each tuple in the array in unsorted order, sorts the array, and then calls ToString to display 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 Tuple<T1, T2, T3>.IComparable.CompareTo 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, 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) };

      Console.WriteLine("The values in unsorted order:");
      foreach (var score in scores)



      Console.WriteLine("The values in sorted order:");
      foreach (var score in scores)
// The example displays the following output;
//    The values in unsorted order:
//    (Jack, 78.8, 8)
//    (Abbey, 92.1, 9)
//    (Dave, 88.3, 9)
//    (Sam, 91.7, 8)
//    (Ed, 71.2, 5)
//    (Penelope, 82.9, 8)
//    (Linda, 99, 9)
//    (Judith, 84.3, 9)
//    The values in sorted order:
//    (Abbey, 92.1, 9)
//    (Dave, 88.3, 9)
//    (Ed, 71.2, 5)
//    (Jack, 78.8, 8)
//    (Judith, 84.3, 9)
//    (Linda, 99, 9)
//    (Penelope, 82.9, 8)
//    (Sam, 91.7, 8)

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Available since 4.0
Windows Phone Silverlight
Available since 8.0
Windows Phone
Available since 8.1
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