VBScript in a Nutshell

Name

InStr, InStrB Functions

Syntax

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

start

Use: Optional

Data Subtype: Numeric

The starting position for the search.

stringtosearch

Use: Required

Data Subtype: String

The string being searched.

stringtofind

Use: Required

Data Subtype: String

The string being sought.

comparemode

Use: Optional

Data Subtype: 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 shown in the following table:

  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 is 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.

• VBScript supports intrinsic constants for comparemode, as follows:

  Comparison Mode	Value	Constant
  Binary (default)	0	vbBinaryCompare
  Text—case insensitive	1	vbTextCompare

  In effect, a binary comparison means that the search for stringtofind in stringtosearch is case-sensitive. A text ...