Unicode string literals in VBA

Question

I would like to declare (in a VBA class module) some private constant strings that contain Japanese characters. Is there a way to construct String literals (or combining literals in a way) that may be accepted as initializers in a Const declaration? i.e. something like:

Private Const MY_CONST = ...

or

Private Const MY_CONST As String = ...

I use MS Excel v14.0.6112.5000 (MS Office Professional Plus 2010).

What won't work:

• Pasting the Japanese chars directly in a string literal (e.g. ... = "変数") because the VBA editor will mess with the chars;
• Using ChrW() or ChrW$() (e.g. ... = ChrW$(22793) & ChrW$(25968)), because function calls are not allowed in Const initializers.

What I wouldn't like:

• Faking the Const by creating Private Property Get returning the string, because the string will be recreated every time I access the property (plus, is confusing and ugly... but, okay, the last two things are rather a matter of taste).

Answer 1

Faking the Const by creating Private Property Get returning the string, because the string will be recreated every time I access the property (plus, is confusing and ugly... but, okay, the last two things are rather a matter of taste).

You need not recreate the string each time you access the property.

While this is still ugly as a matter of taste, make a read-only property (essentially Const, since it doesn't have a Property Let procedure), and construct the string in the Class_Initialize event:

'## CLASS MODULE
Private pUnicodeString As String

Sub Class_Initialize()
    pUnicodeString = ChrW(22793) & ChrW(25968)
End Sub

Property Get UnicodeString() As String
    UnicodeString = pUnicodeString
End Property

And then invoke it like:

'## STANDARD MODULE
Sub Test()
Dim c As myClass
Set c = New myClass

[A1].Value = c.UnicodeString

End Sub

Answer 2

The encoding of VBA source file is Windows-1252, which does not support Japanese.

You cannot change the encoding of the source file, so you have to write its binary equivalent and then convert it before using it

Const str = vbTab & "Ype" ' I use vbTab because the VBA editor replaces tabulation with spaces
'...
ustr = StrConv(str, vbFromUnicode)
'ustr value is now "変数"

Use notepad to convert the string: copy-paste the unicode string, save the file as unicode (not utf-8) and open it as ANSI, then copy-paste it into the VBA editor without the first two characters (ÿþ), which is the BOM marker

Explanation

変数 is U+5909 U+6570 in unicode which is 0x09 0x59 0x70 0x65 in UTF-16LE (Windows unicode encoding), and this sequence corresponds to <tab>Ype in Windows-1252

Answer 3

Another approach is to use an Enum in combination with a function to provide VBA autocomplete based on friendly names. I prefer this method because it keeps all the Unicode definitions in one place, and uses the readable names throughout the rest of my project.

' List friendly names of Unicode characters
Public Enum eUnicodeConst
    RightArrow
    LeftArrow
    Clock2
End Enum

'---------------------------------------------------------------------------------------
' Procedure : UniConst
' Author    : Adam Waller
' Date      : 7/7/2020
' Purpose   : Search for characters: https://emojipedia.org/
'           : Look up UTF-16 Decimal value(s) from the following site:
'           : http://www.fileformat.info/info/unicode/char/search.htm
'---------------------------------------------------------------------------------------
'
Public Function UniConst(Text As eUnicodeConst) As String
    Select Case Text
        Case LeftArrow:     UniConst = ChrW(8592)
        Case RightArrow:    UniConst = ChrW(8594)
        Case Clock2:        UniConst = ChrW(55357) & ChrW(56657)
    End Select
End Function

Now in my code, I can just use the UniConst function anytime I need a Unicode character or snippet without having to look character codes.