# IComparer<T>.Compare(T, T)IComparer<T>.Compare(T, T)IComparer<T>.Compare(T, T)IComparer<T>.Compare(T, T) Method

## Definition

Compares two objects and returns a value indicating whether one is less than, equal to, or greater than the other.

``````public:
int Compare(T x, T y);``````
``public int Compare (T x, T y);``
``abstract member Compare : 'T * 'T -> int``
``Public Function Compare (x As T, y As T) As Integer``
Parameters
x

The first object to compare.

y

The second object to compare.

Returns

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`.

## Examples

The following example implements the IComparer<T> interface to compare objects of type `Box` according to their dimensions. This example is part of a larger example provided for the Comparer<T> class.

``````// This class is not demonstrated in the Main method
// and is provided only to show how to implement
// the interface. It is recommended to derive
// from Comparer<T> instead of implementing IComparer<T>.
public class BoxComp : IComparer<Box>
{
// Compares by Height, Length, and Width.
public int Compare(Box x, Box y)
{
if (x.Height.CompareTo(y.Height) != 0)
{
return x.Height.CompareTo(y.Height);
}
else if (x.Length.CompareTo(y.Length) != 0)
{
return x.Length.CompareTo(y.Length);
}
else if (x.Width.CompareTo(y.Width) != 0)
{
return x.Width.CompareTo(y.Width);
}
else
{
return 0;
}
}
}
``````
``````' This class is not demonstrated in the Main method
' and is provided only to show how to implement
' the interface. It is recommended to derive
' from Comparer<T> instead of implementing IComparer<T>.
Public Class BoxComp
Implements IComparer(Of Box)
' Compares by Height, Length, and Width.
Public Function Compare(ByVal x As Box, ByVal y As Box) As Integer Implements _
IComparer(Of Box).Compare
If x.Height.CompareTo(y.Height) <> 0 Then
Return x.Height.CompareTo(y.Height)
ElseIf x.Length.CompareTo(y.Length) <> 0 Then
Return x.Length.CompareTo(y.Length)
ElseIf x.Width.CompareTo(y.Width) <> 0 Then
Return x.Width.CompareTo(y.Width)
Else
Return 0
End If
End Function
End Class
``````

## Remarks

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

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.