Viacheslav Eremin | Visual Basic Language Reference

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

Public Function InStrRev(
   ByVal StringCheck As String,
   ByVal StringMatch As String,
   Optional ByVal Start As Integer = -1,
   Optional ByVal Compare As CompareMethod = CompareMethod.Binary
) As Integer

Parameters

StringCheck: Required. String expression being searched.
StringMatch: Required. String expression being searched for.
Start: Optional. Numeric expression that sets the one-based starting position for each search, starting from the left side of the string. If Start is omitted, –1 is used, which means that the search begins at the last character position. Search then proceeds from right to left.
Compare: Optional. Numeric value indicating the kind of comparison to use when evaluating substrings. If omitted, a binary comparison is performed. See Settings for values.

Settings

The Compare argument can have the following values:

Constant	Description
Binary	Performs a binary comparison
Text	Performs a textual comparison

Return Values

InStrRev returns the following values:

If	InStrRev returns
StringCheck is zero-length	0
StringMatch is zero-length	start
StringMatch is not found	0
StringMatch is found within StringCheck	Position at which the first match is found, starting with the left side of the string.
Start is greater than length of StringMatch	0

Exceptions/Errors

Exception type	Error number	Condition
ArgumentException	5	Start = 0 or Start < -1.

Remarks

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

Example

This example demonstrates the use of the InStrRev function:

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