InStrfunction

Locates the first occurrence of a substring or character within a string

Syntax

Declare Function InStr ( ByRef str As Const String, [ Any ] ByRef substring As Const String ) As Integer

Declare Function InStr ( ByRef str As Const WString, [ Any ] ByRef substring As Const WString ) As Integer

Declare Function InStr ( ByVal start As Integer, ByRef str As Const String, [ Any ] ByRef substring As Const String ) As Integer

Declare Function InStr ( ByVal start As Integer, ByRef str As Const WString, [ Any ] ByRef substring As Const WString ) As Integer

Parameters

Name		Description
`str`		The string where to search.
`substring`		The substring to find.
`start`		The position in
`str`		at which the search will begin. The first character starts at position 1.

Return value

The position of the first occurrence of substring in str.

Description

Locates the position of the first occurrence of a substring or character within a string. In the first form of InStr (without start parameter), the search begins at the first character.

Zero (0) is returned if: either substring is not found, either str or substring are empty strings, or start < 1.

If the Any keyword is specified, InStr returns the first occurrence of any character in substring.

Remarks

Usage



first = InStr( [ start, ] str, [ Any ] substring )

Platform Differences

The wide-character string version of InStr is not supported for DOS target.

Differences from QB

QB returns start if search is a zero length string.
QB does not support Unicode.

Example

' It will return 4

Print InStr("abcdefg", "de")



' It will return 0

Print InStr("abcdefg", "h")



' It will search for any of the characters "f", "b", "c", and return 2 as "b" is encountered first

Print InStr("abcdefg", Any "fbc")

Dim test As String

Dim idx As Integer



test = "abababab"

idx = InStr(test, "b")



Do While idx > 0 'if not found loop will be skipped

    Print """b"" at " & idx

    idx = InStr(idx + 1, Test, "b")

Loop

'A Unicode example:
dim text as wstring*20
text = "Привет, мир!"
print instr(text,"ет") ' displays 5

Reference

Documented in KeyPgInstr.html