VB.NET Language in a Nutshell, Second Edition

Name

InStrRev Function

Class

Microsoft.VisualBasic.Strings

Syntax

InstrRev(stringcheck, stringmatch[, start[, compare]])

stringcheck (required; String)

The string to be searched.

stringmatch (required; String)

The substring to be found within stringcheck.

start (optional; Numeric)

The starting position of the search. If no value is specified, start defaults to 1.

compare (optional; CompareMethod enumeration)

A constant indicating how stringcheck and stringmatch should be compared.

Return Value

Long

Description

Determines the starting position of a substring within a string by searching from the end of the string to its beginning

Rules at a Glance

• While InStr searches a string from left to right, InStrRev searches a string from right to left.

• The compare argument can be one of CompareMethod.Binary (for a case- sensitive search) or CompareMethod.Text (for a case-insensitive search). If compare is omitted, the type of comparison is binary. Note that Option Compare is not used, unlike with the InStr function.

• start designates the starting point of the search as counted from the start of stringcheck. To start the search at the end of stringcheck, either omit the start argument or set it to -1.

• If stringmatch is not found, InStrRev returns 0.

• If stringmatch is found within stringcheck, the value returned by InStrRev is the position of stringcheck from the start of the string.

Example

This example uses both InStr and InStrRev to highlight the different results produced by each. Using a stringcheck ...