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

public:
 int Compare(T x, T y);

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

Returns

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

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.

See also

• IComparable<T>
• CurrentCulture
• CompareInfo
• CultureInfo