InStr Function

Returns the position of the first occurrence of one string within another.

                      InStr([start, ]string1, string2[, compare])

Arguments

  • start
    Optional. Numeric expression that sets the starting position for each search. The first character position is position 1. If this argument is omitted, search starts at the first character position.

    If the compare argument is specified, a start argument is required.

  • string1
    Required. String expression being searched.

  • string2
    Required. String expression searched for.

  • compare
    Optional. Numeric value indicating the kind of comparison to use when evaluating substrings. See Settings section for values. If this argument is omitted, a binary comparison is performed.

    If this argument is specified, a start argument is required.

Settings

The compare argument can have the following values:

Constant

Value

Description

vbBinaryCompare

0

Perform a binary comparison.

vbTextCompare

1

Perform a textual comparison.

Return Value

The InStr function returns the following values:

If

InStr returns

string1 is zero-length

0

string1 is Null

Null

string2 is zero-length

start

string2 is Null

Null

string2 is not found

0

string2 is found within string1

Position at which match is found

start > Len(string1)

0

Remarks

The following examples use InStr to search a string:

Dim MyPos

' This is a binary comparison because the last argument is omitted.
' Returns 3.
MyPos = InStr ("abcdefgh", "c")

' In this binary comparison, the uppercase "C" is not found
' in the lowercase string.
' Returns 0 (not found).
MyPos = InStr ("abcdefgh", "C")

' In this text comparison starting at the first position,
' the uppercase "C" is found in the lowercase string.
' Returns 3.
MyPos = InStr (1, "abcdefgh", "C", vbTextCompare)

Note

The InStrB function is used with byte data contained in a string. Instead of returning the character position of the first occurrence of one string within another, InStrB returns the byte position.

Requirements

Version 1

See Also

Reference

InStrRev Function

Change History

Date

History

Reason

September 2010

Modified argument definitions.

Customer feedback.

April 2009

Modified example and start argument definition.

Customer feedback.