InStr Function
Returns the position of the first occurrence of one string within another.
Syntax
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
Change History
Date |
History |
Reason |
|---|---|---|
September 2010 |
Modified argument definitions. |
Customer feedback. |
April 2009 |
Modified example and start argument definition. |
Customer feedback. |