Mid Statement
Replaces a specified number of characters in a String
variable with characters from another string.
Syntax
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 | Condition |
---|---|
ArgumentException | Start <= 0 or Length < 0. |
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.
Note
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)