Vbs Tutorial: function-instr Function

Instr Functions

Returns the position where a string appears for the first time in another string.

Instr ([Start,] string1, string2 [, compare])

Parameters

Start

Optional. Value expression, used to set the start position of each search. If omitted, the search starts from the first character. IfStartIf it contains null, an error occurs. IfCompare, You must haveStartParameters.

String1

Required. String expression to be searched.

String2

Required. The string expression to be searched.

Compare

Optional. Indicates the value of the comparison type used to calculate the substring. For values, see the "Settings" section. If omitted, binary comparison is executed.

Set

CompareParameters can have the following values:

Constant	Value	Description
Vbbinarycompare	0	Perform binary comparison.
Vbtextcompare	1	Execute text comparison.

Return Value

InstrThe function returns the following values:

If	Instr return
String1 0 Length	0
String1 is null	Null
String2 0 Length	Start
String2 is null	Null
String2 not found	0
Find string2 in string1	Locate the position that matches the string
Start> Len (string2)	0

Description

The following example usesInstrSearch string:

Dim searchstring, searchchar, mypossearchstring = "xxpxxpxxpxxp" 'string to search in. searchchar = "p" 'search for "p". Mypos =Instr (4,Searchstring,Searchchar,1)     'A textual comparison starting at position 4. Returns 6.  Mypos =Instr (1,Searchstring,Searchchar,0)     'A binary comparison starting at position 1. Returns 9.  Mypos =Instr (Searchstring,Searchchar)    'Comparison is binary by default (last argument is omitted). Returns 9.  Mypos =Instr (1,Searchstring,"W")     'A binary comparison starting at position 1. returns 0 ("W" is not found ). 

Note: Limit BThe function uses the byte data contained in the string, soLimit BThe returned result is not the first occurrence of a character string in another string, but the byte position.