Tuple<T1, T2, T3, T4, T5, T6, T7>::IStructuralComparable::CompareTo Method (Object^, IComparer^)


Compares the current Tuple<T1, T2, T3, T4, T5, T6, T7> 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)

virtual int CompareTo(
	Object^ other,
	IComparer^ comparer
) sealed = IStructuralComparable::CompareTo


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.

This member is an explicit interface implementation. It can be used only when the Tuple<T1, T2, T3, T4, T5, T6, T7> instance is cast to an IStructuralComparable interface.

This method lets you define customized comparisons of Tuple<T1, T2, T3, T4, T5, T6, T7> objects. For example, you can use this method to order Tuple<T1, T2, T3, T4, T5, T6, T7> objects based on the value of a specific component.

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.


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 creates an array of Tuple<T1, T2, T3, T4, T5, T6, T7> objects that contains population data for three U.S. cities from 1950 to 2000. The septuple's first component is the city name. The remaining five components represent the population at 10-year intervals from 1950 to 2000.

The PopulationComparer class provides an IComparer implementation that allows the array of septuples to be sorted by any one of its components. Two values are provided to the PopulationComparer class in its constructor: The position of the component that defines the sort order, and a Boolean value that indicates whether the tuple objects should be sorted in ascending or descending order.

The example then displays the elements in the array in unsorted order, sorts them by the third component (the population in 1960) and displays them, and then sorts them by the sixth component (the population in 1990) and displays them.

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

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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