This documentation is archived and is not being maintained.

String.LastIndexOf Method (String, Int32)

Reports the index position of the last occurrence of a specified String within this instance. The search starts at a specified character position.

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

'Declaration
Public Function LastIndexOf ( _
	value As String, _
	startIndex As Integer _
) As Integer
'Usage
Dim instance As String
Dim value As String
Dim startIndex As Integer
Dim returnValue As Integer

returnValue = instance.LastIndexOf(value, startIndex)
public int LastIndexOf (
	String value, 
	int startIndex
)
public function LastIndexOf (
	value : String, 
	startIndex : int
) : int
Not applicable.

Parameters

value

The String to seek.

startIndex

The search starting position.

Return Value

The index position of value if that string is found, or -1 if it is not. If value is Empty, the return value is startIndex.

Exception typeCondition

ArgumentNullException

value is a null reference (Nothing in Visual Basic).

ArgumentOutOfRangeException

startIndex is less than zero or specifies a position not within this instance.

Index numbering starts from zero.

This method performs a word (case-sensitive and culture-sensitive) search using the current culture. The search begins at the startIndex character position of this instance and proceeds backwards towards the beginning until either value is found or the first character position has been examined.

The following code example finds the index of all occurrences of a string in target string, working from the end of the target string to the start of the target string.

' Sample for String.LastIndexOf(String, Int32)
Imports System
 _

Class Sample
   
   Public Shared Sub Main()
      
      Dim br1 As String = "0----+----1----+----2----+----3----+----4----+----5----+----6----+-"
      Dim br2 As String = "0123456789012345678901234567890123456789012345678901234567890123456"
      Dim str As String = "Now is the time for all good men to come to the aid of their party."
      Dim start As Integer
      Dim at As Integer

      '#3
      start = str.Length - 1
      Console.WriteLine("All occurrences of 'he' from position {0} to 0.", start)
      Console.WriteLine("{1}{0}{2}{0}{3}{0}", Environment.NewLine, br1, br2, str)
      Console.Write("The string 'he' occurs at position(s): ")
      
      at = 0
      While start > - 1 And at > - 1
         at = str.LastIndexOf("he", start)
         If at > - 1 Then
            Console.Write("{0} ", at)
            start = at - 1
         End If
      End While
      Console.Write("{0}{0}{0}", Environment.NewLine)
   End Sub 'Main 
End Class 'Sample
'
'This example produces the following results:
'All occurrences of 'he' from position 66 to 0.
'0----+----1----+----2----+----3----+----4----+----5----+----6----+-
'0123456789012345678901234567890123456789012345678901234567890123456
'Now is the time for all good men to come to the aid of their party.
'
'The string 'he' occurs at position(s): 56 45 8
'
'

// Sample for String.LastIndexOf(String, Int32)
import System.*;

class Sample
{
    public static void main(String[] args)
    {
        String br1 = "0----+----1----+----2----+----3----+----4----+----5----+"
            + "----6----+-";
        String br2 = "01234567890123456789012345678901234567890123456789012345"
            + "67890123456";
        String str = "Now is the time for all good men to come to the aid of "
            + "their party.";
        int start;
        int at;

        start = str.get_Length() - 1;
        Console.WriteLine("All occurrences of 'he' from position {0} to 0.",
            (Int32)start);
        Console.Write("{1}{0}", Environment.get_NewLine(), br1);
        Console.Write("{1}{0}", Environment.get_NewLine(), br2);
        Console.WriteLine("{1}{0}", Environment.get_NewLine(), str);
        Console.Write("The string 'he' occurs at position(s): ");

        at = 0;
        while (start > -1 && at > -1) {
            at = str.LastIndexOf("he", start);
            if (at > -1) {
                Console.Write("{0} ", (Int32)at);
                start = at - 1;
            }
        }
        Console.Write("{0}{0}{0}", Environment.get_NewLine());
    } //main
} //Sample
/*
This example produces the following results:
All occurrences of 'he' from position 66 to 0.
0----+----1----+----2----+----3----+----4----+----5----+----6----+-
0123456789012345678901234567890123456789012345678901234567890123456
Now is the time for all good men to come to the aid of their party.

The string 'he' occurs at position(s): 56 45 8


*/

Windows 98, Windows Server 2000 SP4, Windows CE, Windows Millennium Edition, Windows Mobile for Pocket PC, Windows Mobile for Smartphone, Windows Server 2003, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP SP2, Windows XP Starter Edition

The Microsoft .NET Framework 3.0 is supported on Windows Vista, Microsoft Windows XP SP2, and Windows Server 2003 SP1.

.NET Framework

Supported in: 3.0, 2.0, 1.1, 1.0

.NET Compact Framework

Supported in: 2.0, 1.0

XNA Framework

Supported in: 1.0
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