Tuple<T1>.IStructuralComparable.CompareTo Method
Compares the current Tuple<T1> 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)
Parameters
- other
- Type: System.Object
An object to compare with the current instance.
- comparer
- Type: System.Collections.IComparer
An object that provides custom rules for comparison.
Return Value
Type: System.Int32A signed integer that indicates the relative position of this instance and other in the sort order, as shown in the following table.
Value | Description |
|---|---|
A negative integer | This instance precedes other. |
Zero | This instance and other have the same position in the sort order. |
A positive integer | This instance follows other. |
Implements
IStructuralComparable.CompareTo(Object, IComparer)| Exception | Condition |
|---|---|
| ArgumentException | other is not a Tuple<T1> object. |
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 |
|---|
The 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 IStructuralEquatable.Equals method. |
The following example defines a generic class named DescendingComparer that implements the IComparer<T> interface. DescendingComparer sorts objects in descending rather than ascending order by reversing the value returned by the default comparer for a particular type. An instance of the generic DescendingComparer class is then passed to the Array.Sort(Array, IComparer) method to sort an array of Tuple<T1> objects in descending order. Note that the example does not directly call the IStructuralComparable.CompareTo method. This method is called implicitly by the Array.Sort(Array, IComparer) method for each element in the array.
using System; using System.Collections.Generic; public class DescendingComparer<T> : IComparer<T> { public int Compare(T x, T y) { return -1 * Comparer<T>.Default.Compare(x, y); } } class CompareTo2 { static void Main() { Tuple<Double>[] values = { Tuple.Create(13.54), Tuple.Create(Double.NaN), Tuple.Create(-189.42993), Tuple.Create(Double.PositiveInfinity), Tuple.Create(Double.Epsilon), Tuple.Create(1.934E-17), Tuple.Create(Double.NegativeInfinity), Tuple.Create(-0.000000000003588), null }; Console.WriteLine("The values in unsorted order:"); foreach (var value in values) if (value != null) Console.WriteLine(" {0}", value.Item1); else Console.WriteLine(" <null>"); Console.WriteLine(); Array.Sort(values, new DescendingComparer<Tuple<Double>>()); Console.WriteLine("The values sorted in descending order:"); foreach (var value in values) if (value != null) Console.WriteLine(" {0}", value.Item1); else Console.WriteLine(" <null>"); } } // The example displays the following output: // The values in unsorted order: // 13.54 // NaN // -189.42993 // Infinity // 4.94065645841247E-324 // 1.934E-17 // -Infinity // -3.588E-12 // <null> // // The values sorted in descending order: // Infinity // 13.54 // 1.934E-17 // 4.94065645841247E-324 // -3.588E-12 // -189.42993 // -Infinity // NaN // <null>
Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)
The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
