`AscW` Function

Returns an Integer representing the Unicode character code of the first character in a string. The "W" suffix indicates this is the wide (Unicode) version of the Asc function.

Syntax

AscW(string)

Parameters

string: Required. Any valid string expression. If the string contains no characters, a runtime error occurs (Error 5: Invalid procedure call or argument).

Returns

Returns an Integer representing the Unicode code point (0-65535) of the first character in the string.

Remarks

AscW returns the Unicode (UTF-16) code point of the first character in a string.
The W suffix stands for "Wide", distinguishing it from the ANSI AscB function.
Return values range from 0 to 65535, covering the Basic Multilingual Plane (BMP) of Unicode.
For ASCII characters (0-127), AscW and Asc return the same values.
For characters in the extended ASCII range (128-255), results match the Latin-1 supplement in Unicode.
If the string is empty (""), a runtime error occurs (Error 5).
AscW is essential for working with international text and Unicode characters.
The inverse function is ChrW, which converts a Unicode code point back to a character.
Characters outside the BMP (above 65535) are represented as surrogate pairs in VB6.
Surrogate pair characters will return the code of the high surrogate (0xD800-0xDBFF).

Typical Uses

International text processing - Work with characters from various languages
Unicode character analysis - Examine Unicode code points in strings
Character validation - Validate characters are in expected Unicode ranges
Text encoding operations - Convert between different character encodings
Symbol detection - Identify mathematical symbols, currency, arrows, etc.
Character range checking - Determine if characters belong to specific scripts
Multilingual sorting - Implement custom sort orders based on Unicode values

Basic Examples

' Example 1: Simple ASCII character
Dim code As Integer
code = AscW("A")  ' Returns 65

' Example 2: Euro symbol
Dim euroCode As Integer
euroCode = AscW("€")  ' Returns 8364

' Example 3: Greek letter
Dim alphaCode As Integer
alphaCode = AscW("α")  ' Returns 945

' Example 4: Chinese character
Dim hanziCode As Integer
hanziCode = AscW("中")  ' Returns 20013

Common Patterns

Check Unicode Range

Function IsInUnicodeRange(char As String, rangeStart As Long, rangeEnd As Long) As Boolean
If Len(char) = 0 Then Exit Function
Dim code As Long
code = AscW(char)
IsInUnicodeRange = (code >= rangeStart And code <= rangeEnd)
End Function

Detect Character Script

Function GetCharacterScript(char As String) As String
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

Select Case code
Case 0 To 127
GetCharacterScript = "ASCII"
Case 880 To 1023
GetCharacterScript = "Greek"
Case 1024 To 1279
GetCharacterScript = "Cyrillic"
Case 1424 To 1535
GetCharacterScript = "Hebrew"
Case 1536 To 1791
GetCharacterScript = "Arabic"
Case 19968 To 40959
GetCharacterScript = "CJK"
Case 44032 To 55203
GetCharacterScript = "Hangul"
Case Else
GetCharacterScript = "Other"
End Select
End Function

Validate Latin Characters

Function IsLatinChar(char As String) As Boolean
If Len(char) = 0 Then Exit Function
Dim code As Long
code = AscW(char)
' Basic Latin + Latin-1 Supplement + Latin Extended-A and B
IsLatinChar = (code >= 0 And code <= 591)
End Function

Check for Symbol Characters

Function IsSymbol(char As String) As Boolean
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' Common symbol ranges
IsSymbol = (code >= 8192 And code <= 8303) Or _
(code >= 8352 And code <= 8399) Or _
(code >= 8448 And code <= 8527) Or _
(code >= 8704 And code <= 8959) Or _
(code >= 9632 And code <= 9727)
End Function

Compare Unicode Values

Function CompareUnicode(char1 As String, char2 As String) As Integer
If Len(char1) = 0 Or Len(char2) = 0 Then Exit Function
CompareUnicode = AscW(char1) - AscW(char2)
End Function

Detect Emoji (BMP only)

Function IsEmojiBMP(char As String) As Boolean
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' Emoticons and Miscellaneous Symbols
IsEmojiBMP = (code >= 9728 And code <= 9983) Or _
(code >= 10084 And code <= 10084) Or _
(code >= 127744 And code <= 128511)
End Function

Extract Unicode Array

Function GetUnicodeArray(text As String) As Variant
Dim codes() As Long
Dim i As Long

If Len(text) = 0 Then Exit Function

ReDim codes(1 To Len(text))
For i = 1 To Len(text)
codes(i) = AscW(Mid(text, i, 1))
Next i

GetUnicodeArray = codes
End Function

Check Diacritical Marks

Function IsDiacriticalMark(char As String) As Boolean
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' Combining Diacritical Marks
IsDiacriticalMark = (code >= 768 And code <= 879)
End Function

Validate Email Characters

Function IsValidEmailChar(char As String) As Boolean
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' Alphanumeric, dot, hyphen, underscore, @
IsValidEmailChar = (code >= 48 And code <= 57) Or _
(code >= 65 And code <= 90) Or _
(code >= 97 And code <= 122) Or _
code = 45 Or code = 46 Or code = 64 Or code = 95
End Function

Detect Control Characters

Function IsUnicodeControl(char As String) As Boolean
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' C0 and C1 control characters
IsUnicodeControl = (code >= 0 And code <= 31) Or _
(code >= 127 And code <= 159)
End Function

Advanced Examples

Unicode Normalization Check

Function CompareNormalized(str1 As String, str2 As String) As Boolean
' Simple comparison ignoring case
If Len(str1) <> Len(str2) Then
CompareNormalized = False
Exit Function
End If

Dim i As Long
Dim code1 As Long, code2 As Long

For i = 1 To Len(str1)
code1 = AscW(Mid(str1, i, 1))
code2 = AscW(Mid(str2, i, 1))

' Convert to lowercase if uppercase Latin
If code1 >= 65 And code1 <= 90 Then code1 = code1 + 32
If code2 >= 65 And code2 <= 90 Then code2 = code2 + 32

If code1 <> code2 Then
CompareNormalized = False
Exit Function
End If
Next i

CompareNormalized = True
End Function

Unicode to HTML Entity

Function UnicodeToHTMLEntity(char As String) As String
If Len(char) = 0 Then Exit Function

Dim code As Long
code = AscW(char)

' Create numeric entity
UnicodeToHTMLEntity = "&#" & code & ";"
End Function

Multilingual Text Analyzer

Function AnalyzeText(text As String) As String
Dim i As Long
Dim code As Long
Dim latinCount As Long
Dim cjkCount As Long
Dim arabicCount As Long
Dim otherCount As Long

For i = 1 To Len(text)
code = AscW(Mid(text, i, 1))

Select Case code
Case 0 To 591
latinCount = latinCount + 1
Case 19968 To 40959
cjkCount = cjkCount + 1
Case 1536 To 1791
arabicCount = arabicCount + 1
Case Else
otherCount = otherCount + 1
End Select
Next i

AnalyzeText = "Latin: " & latinCount & ", CJK: " & cjkCount & _
", Arabic: " & arabicCount & ", Other: " & otherCount
End Function

Character Category Validator

Function ValidateCategory(text As String, category As String) As Boolean
Dim i As Long
Dim code As Long

For i = 1 To Len(text)
code = AscW(Mid(text, i, 1))

Select Case category
Case "Digit"
If Not (code >= 48 And code <= 57) Then
ValidateCategory = False
Exit Function
End If
Case "UpperLatin"
If Not (code >= 65 And code <= 90) Then
ValidateCategory = False
Exit Function
End If
Case "LowerLatin"
If Not (code >= 97 And code <= 122) Then
ValidateCategory = False
Exit Function
End If
Case Else
ValidateCategory = False
Exit Function
End Select
Next i

ValidateCategory = True
End Function

Error Handling

Function SafeAscW(text As String) As Long
On Error GoTo ErrorHandler

If Len(text) = 0 Then
SafeAscW = -1  ' Error indicator
Exit Function
End If

SafeAscW = AscW(text)
Exit Function

ErrorHandler:
SafeAscW = -1
End Function

Performance Notes

AscW is a very fast operation with minimal overhead
When processing long strings character-by-character, use Mid function efficiently
For repeated code point lookups, consider caching results
AscW is faster than string comparison for Unicode operations
No significant performance difference between Asc and AscW on modern systems

Best Practices

Validate input - Always check for empty strings before calling AscW
Use for Unicode - Prefer AscW over Asc when working with international text
Handle errors - Wrap AscW calls in error handlers when processing untrusted input
Document ranges - Use constants or comments to explain Unicode range checks
Consider normalization - Be aware that some characters have multiple Unicode representations
Use with ChrW - Pair with ChrW for Unicode code point conversions
Test edge cases - Verify behavior with empty strings, control characters, and non-BMP characters

Function	Returns	Character Set	Use Case
`Asc`	Integer (0-255 or Unicode)	System default	General character codes
`AscB`	Integer (0-255)	ANSI byte value	Byte-level operations
`AscW`	Integer (0-65535)	Unicode code point	International text
`ChrW`	String (Unicode)	Unicode (inverse)	Convert code to character

Unicode Ranges Reference

Common Unicode ranges that can be detected with AscW:

Basic Latin (ASCII): 0-127
Latin-1 Supplement: 128-255
Latin Extended-A: 256-383
Greek and Coptic: 880-1023
Cyrillic: 1024-1279
Hebrew: 1424-1535
Arabic: 1536-1791
Devanagari: 2304-2431
Thai: 3584-3711
Tibetan: 3840-4095
CJK Unified Ideographs: 19968-40959
Hangul Syllables: 44032-55203
Currency Symbols: 8352-8399
Mathematical Operators: 8704-8959
Arrows: 8592-8703
Box Drawing: 9472-9599
Emoticons: 9728-9983

Platform Notes

VB6 uses UTF-16 internally on Windows NT-based systems for Unicode support
On Windows 95/98/ME, Unicode support is limited and may not work correctly
Modern Windows systems (XP and later) have full Unicode support
AscW returns consistent values across different code pages
For maximum compatibility, test on target platforms with actual Unicode data

Limitations

AscW only returns code points in the Basic Multilingual Plane (0-65535)
Characters outside the BMP require surrogate pairs and special handling
Combining characters are treated as separate code points
Some characters may display differently depending on available fonts
Grapheme clusters (like emoji with modifiers) are not handled as single units
Runtime error occurs with empty strings
No built-in normalization (characters with multiple representations)

AscW Function