String.IComparable.CompareTo(Object) Method

Definition

Compares this instance with a specified Object and indicates whether this instance precedes, follows, or appears in the same position in the sort order as the specified Object.

 virtual int System.IComparable.CompareTo(System::Object ^ value) = IComparable::CompareTo;
int IComparable.CompareTo (object value);
abstract member System.IComparable.CompareTo : obj -> int
override this.System.IComparable.CompareTo : obj -> int
Function CompareTo (value As Object) As Integer Implements IComparable.CompareTo

Parameters

value
Object

An object that evaluates to a String.

Returns

Int32

A 32-bit signed integer that indicates whether this instance precedes, follows, or appears in the same position in the sort order as the value parameter.

ValueCondition
Less than zeroThis instance precedes value.
ZeroThis instance has the same position in the sort order as value.
Greater than zeroThis instance follows value.

-or-

value is null.

Implements

Exceptions

value is not a String.

Examples

The following example uses the CompareTo method with an Object. Because it attempts to compare a String instance to a TestClass object, the method throws an ArgumentException.

using namespace System;

public ref class TestClass{};

int main()
{
   TestClass^ test = gcnew TestClass;
   array<Object^>^ objectsToCompare = { test, test->ToString(), 123,
                                        (123).ToString(), "some text",
                                        "Some Text" };
   String^ s = "some text";
   for each (Object^ objectToCompare in objectsToCompare) {
      try {
         Int32 i = s->CompareTo(objectToCompare);
         Console::WriteLine("Comparing '{0}' with '{1}': {2}",
                            s, objectToCompare, i);
      }
      catch (ArgumentException^ e) {
         Console::WriteLine("Bad argument: {0} (type {1})",
                            objectToCompare,
                            objectToCompare->GetType()->Name);
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1
using System;

public class TestClass
{}

public class Example
{
   public static void Main()
   {
      var test = new TestClass();
      Object[] objectsToCompare = { test, test.ToString(), 123,
                                    123.ToString(), "some text",
                                    "Some Text" };
      string s = "some text";
      foreach (var objectToCompare in objectsToCompare) {
         try {
            int i = s.CompareTo(objectToCompare);
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i);
         }
         catch (ArgumentException) {
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name);
         }
      }
   }
}
// The example displays the following output:
//    Bad argument: TestClass (type TestClass)
//    Comparing 'some text' with 'TestClass': -1
//    Bad argument: 123 (type Int32)
//    Comparing 'some text' with '123': 1
//    Comparing 'some text' with 'some text': 0
//    Comparing 'some text' with 'Some Text': -1
Public Class TestClass
End Class 


Public Class Example
   Public Shared Sub Main()
      Dim test As New TestClass()
      Dim objectsToCompare() As Object = { test, test.ToString(), 123,
                                           123.ToString(), "some text",
                                           "Some Text" }
      Dim s As String = "some text"
      For Each objectToCompare In objectsToCompare
         Try
            Dim i As Integer = s.CompareTo(objectToCompare)
            Console.WriteLine("Comparing '{0}' with '{1}': {2}",
                              s, objectToCompare, i)
         Catch e As ArgumentException
            Console.WriteLine("Bad argument: {0} (type {1})",
                              objectToCompare,
                              objectToCompare.GetType().Name)
         End Try
      Next
   End Sub 
End Class 
' The example displays the following output:
'       Bad argument: TestClass (type TestClass)
'       Comparing 'some text' with 'TestClass': -1
'       Bad argument: 123 (type Int32)
'       Comparing 'some text' with '123': 1
'       Comparing 'some text' with 'some text': 0
'       Comparing 'some text' with 'Some Text': -1

Remarks

value must be a String object.

Caution

The CompareTo method was designed primarily for use in sorting or alphabetizing operations. It should not be used when the primary purpose of the method call is to determine whether two strings are equivalent. To determine whether two strings are equivalent, call the Equals method.

This method performs a word (case-sensitive and culture-sensitive) comparison using the current culture. For more information about word, string, and ordinal sorts, see System.Globalization.CompareOptions.

For more information about the behavior of this method, see the Remarks section of the String.Compare(String, String) method.

Applies to