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Comparer<T>.Compare Method

When overridden in a derived class, performs a comparison of two objects of the same type and returns a value indicating whether one object is less than, equal to, or greater than the other.

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

public abstract int Compare(
	T x,
	T y
)

Parameters

x
Type: T

The first object to compare.

y
Type: T

The second object to compare.

Return Value

Type: System.Int32
A signed integer that indicates the relative values of x and y, as shown in the following table.

Value

Meaning

Less than zero

x is less than y.

Zero

x equals y.

Greater than zero

x is greater than y.

Implements

IComparer<T>.Compare(T, T)

ExceptionCondition
ArgumentException

Type T does not implement either the System.IComparable<T> generic interface or the System.IComparable interface.

Implement this method to provide a customized sort order comparison for type T.

Notes to Implementers:

Comparing null with any reference type is allowed and does not generate an exception. A null reference is considered to be less than any reference that is not null.

For information on culture-specific comparisons, see the System.Globalization namespace and Encoding and Localization.

The following example defines a comparer of Box objects that can be used instead of the default comparer. This example is part of a larger example provided for the Comparer<T> class.

public class BoxLengthFirst : Comparer<Box> 
{
    // Compares by Length, Height, and Width. 
    public override int Compare(Box x, Box y)
    {
        if (x.Length.CompareTo(y.Length) != 0)
        {
            return x.Length.CompareTo(y.Length);
        }
        else if (x.Height.CompareTo(y.Height) != 0)
        {
            return x.Height.CompareTo(y.Height);
        }
        else if (x.Width.CompareTo(y.Width) != 0)
        {
            return x.Width.CompareTo(y.Width);
        }
        else
        {
            return 0;
        }
    }

}

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98, Windows CE, Windows Mobile for Smartphone, Windows Mobile for Pocket PC, Xbox 360, Zune

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

.NET Framework

Supported in: 3.5, 3.0, 2.0

.NET Compact Framework

Supported in: 3.5, 2.0

XNA Framework

Supported in: 3.0, 2.0, 1.0

Date

History

Reason

Added example.

Information enhancement.

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