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Tuple(T1, T2, T3).IStructuralComparable.CompareTo Method

Compares the current Tuple(T1, T2, T3) object to a specified object by using a specified comparer, 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)

private abstract CompareTo : 
        other:Object * 
        comparer:IComparer -> int 
private override CompareTo : 
        other:Object * 
        comparer:IComparer -> int 


Type: System.Object
An object to compare with the current instance.
Type: System.Collections.IComparer
An object that provides custom rules for comparison.

Return Value

Type: System.Int32
A signed integer that indicates the relative position of this instance and other in the sort order, as shown in the following table.



A negative integer

This instance precedes other.


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

A positive integer

This instance follows other.


IStructuralComparable.CompareTo(Object, IComparer)


other 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 IStructuralComparable interface.

Although this method can be called directly, it is most commonly called by collection sorting methods that include IComparer parameters to order the members of a collection. For example, it is called by the Array.Sort(Array, IComparer) method and the Add method of a SortedList object that is instantiated by using the SortedList.SortedList(IComparer) constructor.

Caution noteCaution

The Tuple(T1, T2, T3).IStructuralComparable.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 Tuple(T1, T2, T3).IStructuralEquatable.Equals method.

The following example creates an array of Tuple(T1, T2, T3) objects that consist of a student's name, mean test score, and number of tests. 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. To sort the array, the example defines a generic ScoreComparer class that implements the IComparer interface and sorts the Tuple(T1, T2, T3) objects in ascending order by the value of their second component rather than their first component. Note that the example does not directly call the Tuple(T1, T2, T3).IStructuralComparable.CompareTo method. This method is called implicitly by the Array.Sort(Array, IComparer) method for each element in the array.

No code example is currently available or this language may not be supported.

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.