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

 

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

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

int IComparer.Compare(
	object x,
	object y
)

Parameters

x
Type: System.Object

The first object to compare.

y
Type: System.Object

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.

Exception Condition
ArgumentException

x or y is of a type that cannot be cast to type T.

-or-

x and y do not implement either the System.IComparable<T> generic interface or the System.IComparable interface.

This method is a wrapper for the Compare(T, T) method, so obj must be cast to the type specified by the generic argument T of the current instance. If it cannot be cast to T, an ArgumentException is thrown.

Comparing null with any reference type is allowed and does not generate an exception. When sorting, null is considered to be less than any other object.

Notes to Callers:

Compare and EqualityComparer<T>.Equals behave differently in terms of culture-sensitivity and case-sensitivity.

For string comparisons, the StringComparer class is recommended over Comparer<String>. Properties of the StringComparer class return predefined instances that perform string comparisons with different combinations of culture-sensitivity and case-sensitivity. The case-sensitivity and culture-sensitivity are consistent among the members of the same StringComparer instance.

For more information on culture-specific comparisons, see the System.Globalization namespace and Globalizing and Localizing .NET Framework Applications.

The following example shows how to use the IComparer.Compare method to compare two objects. This example is part of a larger example provided for the Comparer<T> class.


// This explicit interface implementation
// compares first by the length.
// Returns -1 because the length of BoxA
// is less than the length of BoxB.
BoxLengthFirst LengthFirst = new BoxLengthFirst(); 

Comparer<Box> bc = (Comparer<Box>) LengthFirst;

Box BoxA = new Box(2, 6, 8);
Box BoxB = new Box(10, 12, 14);
int x = LengthFirst.Compare(BoxA, BoxB);
Console.WriteLine();
Console.WriteLine(x.ToString());

Universal Windows Platform
Available since 4.5
.NET Framework
Available since 2.0
Portable Class Library
Supported in: portable .NET platforms
Silverlight
Available since 2.0
Windows Phone Silverlight
Available since 7.0
Windows Phone
Available since 8.1
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