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Strings.InStrRev Method

Returns the position of the first occurrence of one string within another, starting from the right side of the string.

Namespace:  Microsoft.VisualBasic
Assembly:  Microsoft.VisualBasic (in Microsoft.VisualBasic.dll)

Public Shared Function InStrRev ( _
	StringCheck As String, _
	StringMatch As String, _
	Start As Integer, _
	Compare As CompareMethod _
) As Integer


Type: System.String
Required. String expression being searched.
Type: System.String
Required. String expression being searched for.
Type: System.Int32
Optional. Numeric expression setting the one-based starting position for each search, starting from the left side of the string. If Start is omitted then –1 is used, meaning the search begins at the last character position. Search then proceeds from right to left.
Type: Microsoft.VisualBasic.CompareMethod
Optional. Numeric value indicating the kind of comparison to use when evaluating substrings. If omitted, a binary comparison is performed. See Settings for values.

Return Value

Type: System.Int32


InStrRev returns

StringCheck is zero-length


StringMatch is zero-length


StringMatch is not found


StringMatch is found within StringCheck

Position at which the first match is found, starting with the right side of the string.

Start is greater than length of StringMatch



Start = 0 or Start < -1.

Note that the syntax for the InStrRev function is not the same as the syntax for the InStr function.

The Compare argument can have the following values.




Performs a binary comparison.


Performs a textual comparison.

This example demonstrates the use of the InStrRev function.

Dim TestString As String = "the quick brown fox jumps over the lazy dog"
Dim TestNumber As Integer
' Returns 32.
TestNumber = InStrRev(TestString, "the")
' Returns 1.
TestNumber = InStrRev(TestString, "the", 16)

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0, 1.1, 1.0

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.