Asc, AscW Functions
Returns an Integer value representing the character code corresponding to a character.
Public Overloads Function Asc(ByVal String As Char) As Integer
Public Overloads Function AscW(ByVal String As Char) As Integer
' -or-
Public Overloads Function Asc(ByVal String As String) As Integer
Public Overloads Function AscW(ByVal String As String) As Integer
Parameters
- String
Required. Any valid Char or String expression. If String is a String expression, only the first character of the string is used for input. If String is Nothing or contains no characters, an ArgumentException error occurs.
Exceptions
| Exception type | Error number | Condition |
|---|---|---|
ArgumentException |
String is empty or is zero length. |
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 (Err Object).) However, when possible, you should consider replacing such error control with Structured Exception Handling Overview for Visual Basic.
Remarks
Asc returns the code point, or character code, for the input character. This can be 0 through 255 for single-byte character set (SBCS) values and -32768 through 32767 for double-byte character set (DBCS) values. For charts of the single-byte ASCII characters, see ASCII Character Codes.
The returned value depends on the code page for the current thread, which is contained in the ANSICodePage property of the TextInfo class in the System.Globalization namespace. You can obtain ANSICodePage by specifying System.Globalization.CultureInfo.CurrentCulture.TextInfo.ANSICodePage.
AscW returns the Unicode code point for the input character. This can be 0 through 65535. The returned value is independent of the culture and code page settings for the current thread.
Note
The AscB function of earlier versions of Visual Basic returns a code for a byte, rather than a character. It is used primarily for converting strings in double-byte character set (DBCS) applications. All Visual Basic 2005 strings are in Unicode, and AscB is no longer supported.
Example
The following example uses the Asc function to return Integer Data Type (Visual Basic) character codes corresponding to the first letter in each string.
Dim codeInt As Integer
' The following line of code sets myInt to 65.
codeInt = Asc("A")
' The following line of code sets myInt to 97.
codeInt = Asc("a")
' The following line of code sets myInt to 65.
codeInt = Asc("Apple")
Requirements
Namespace: Microsoft.VisualBasic
Module: Strings
Assembly: Visual Basic Runtime Library (in Microsoft.VisualBasic.dll)
See Also
Reference
Chr, ChrW Functions
Conversion Functions (Visual Basic)
Type Conversion Functions
Integer Data Type (Visual Basic)
System.Globalization
CultureInfo
ANSICodePage
ArgumentException