Mid Statement
Replaces a specified number of characters in a String variable with characters from another string.
Mid( _
ByRef Target As String, _
ByVal Start As Integer, _
Optional ByVal Length As Integer _
) = StringExpression
Parts
Target
Required. Name of the String variable to modify.Start
Required. Integer expression. Character position in Target where the replacement of text begins. Start uses a one-based index.Length
Optional. Integer expression. Number of characters to replace. If omitted, all of String is used.StringExpression
Required. String expression that replaces part of Target.
Exceptions
Exception type |
Error number |
Condition |
|---|---|---|
5 |
Start <= 0 or Length < 0. |
See the "Error number" column if you are upgrading Visual Basic 6.0 applications that use unstructured error handling. (You can compare the error number against the Number property.) However, when possible, you should consider replacing such error control with Structured Exception Handling Overview for Visual Basic.
Remarks
The number of characters replaced is always less than or equal to the number of characters in Target.
Visual Basic has a Mid function and a Mid statement. These elements both operate on a specified number of characters in a string, but the Mid function returns the characters while the Mid statement replaces the characters. For more information, see Mid.
Poznámka
The MidB statement of earlier versions of Visual Basic replaces a substring in bytes, rather than characters. It is used primarily for converting strings in double-byte character set (DBCS) applications. All Visual Basic strings are in Unicode, and MidB is no longer supported.
Example
This example uses the Mid statement to replace a specified number of characters in a string variable with characters from another string.
Dim TestString As String
' Initializes string.
TestString = "The dog jumps"
' Returns "The fox jumps".
Mid(TestString, 5, 3) = "fox"
' Returns "The cow jumps".
Mid(TestString, 5) = "cow"
' Returns "The cow jumpe".
Mid(TestString, 5) = "cow jumped over"
' Returns "The duc jumpe".
Mid(TestString, 5, 3) = "duck"
Requirements
Namespace: Microsoft.VisualBasic
Module: Strings
Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)