Len Function

Returns a Long containing the number of characters in a string or the number of bytes required to store avariable. Syntax Len ( string | varname ) The Len function syntax has these parts:

Part Description
string Any valid string expression. If string containsNull, Null is returned.
Varname Any valid variable name. If varname contains Null, Null is returned. If varname is aVariant, Len treats it the same as a String and always returns the number of characters it contains.

Remarks One (and only one) of the two possible arguments must be specified. Withuser-defined types, Len returns the size as it will be written to the file.

Note Use the LenB function with byte data contained in a string, as in double-byte character set (DBCS) languages. Instead of returning the number of characters in a string, LenB returns the number of bytes used to represent that string. With user-defined types, LenB returns the in-memory size, including any padding between elements. For sample code that uses LenB, see the second example in the example topic.

Note Len may not be able to determine the actual number of storage bytes required when used with variable-length strings in user-defineddata types.


The first example uses Len to return the number of characters in a string or the number of bytes required to store a variable. The Type...End Type block defining CustomerRecord must be preceded by the keyword Private if it appears in a class module. In a standard module, a Type statement can be Public.

Type CustomerRecord    ' Define user-defined type.
    ID As Integer    ' Place this definition in a 
    Name As String * 10    ' standard module.
    Address As String * 30
End Type

Dim Customer As CustomerRecord    ' Declare variables.
Dim MyInt As Integer, MyCur As Currency
Dim MyString, MyLen
MyString = "Hello World"    ' Initialize variable.
MyLen = Len(MyInt)    ' Returns 2.
MyLen = Len(Customer)    ' Returns 42.
MyLen = Len(MyString)    ' Returns 11.
MyLen = Len(MyCur)    ' Returns 8.

The second example uses LenB and a user-defined function (LenMbcs) to return the number of byte characters in a string if ANSI is used to represent the string.

Function LenMbcs (ByVal str as String)
    LenMbcs = LenB(StrConv(str, vbFromUnicode))
End Function

Dim MyString, MyLen
MyString = "ABc"
' Where "A" and "B" are DBCS and "c" is SBCS.
MyLen = Len(MyString)
' Returns 3 - 3 characters in the string.
MyLen = LenB(MyString)
' Returns 6 - 6 bytes used for Unicode.
MyLen = LenMbcs(MyString)
' Returns 5 - 5 bytes used for ANSI.