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InStr

Returns the position of the first match, or 0 if there is none.

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

• str
• substring
• start
• 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.

Return Value

The position of the first occurrence of substring in str.

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.

See also

• InStrRev
• Mid (Function)

Examples

' 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

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Category: String Functions
Kind: function

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