VB & VBA in a Nutshell: The Language

InStr, InStrB Functions

Named Arguments

No

Syntax

InStr([start, ]stringtosearch, stringtofind[, _
      comparemode])

start

Use: Optional

Data Type: Numeric

The starting position for the search.

stringtosearch

Use: Required

Data Type: String

The string being searched.

stringtofind

Use: Required

Data Type: String

The string being sought.

comparemode

Use: Optional

Data Type: Integer

The type of string comparison.

Return Value

A variant of subtype Long.

Description

Finds the starting position of one string within another.

Rules at a Glance

• The return value of InStr is influenced by the values of stringtosearch and stringtofind, as the following table details:

  Condition	InStr Return Value
  stringtosearch is zero-length	0
  stringtosearch is Null	Null
  stringtofind is zero-length	start
  stringtofind is Null	Null
  stringtofind is not found	0
  stringtofind found within stringtosearch	Position at which the start of stringtofind is found
  start > len(stringtofind)	0

• If the start argument is omitted, InStr commences the search with the first character of stringtosearch.

• If the start argument is Null, an error occurs.

• You must specify a start argument if you are specifying a comparemode argument.

• VB5 and VBA support intrinsic constants for comparemode, as follows:

  Comparison Mode	Value	Constant
  Binary (default)	0	vbBinaryCompare
  Text—case insensitive	1	vbTextCompare
  Database (Microsoft Access only)	2	vbDatabaseCompare

• If the comparemode argument contains Null, an error is generated.

• If comparemode is ...