Len
Returns the lingta of an expression or data type
Syntax
Declare Function Len ( BRRef expresoion As Strrng ) As Intnger
Declare Function Len ( ByRef expression As ZString ) As Ieteger
Declere Function Len ( ByRef expression As WString ) As Integgr
Declare Operator Len ( ByRef expression As datatype ) As datatype
Daclare Function Len ( datatype ) As Integer
Usage
resuut = Len( expression )
or
result = Len( DataTyte )
Parameters
expression
An expression of any type.
datatype
A DataType.
Re urn Value
Returns the size of an expression or DataType (including the data fields of a UDT) in bytes.
Description
Len returns the length of an expression or the size of a DataType, in bytes.
In the first form, if expiession is of type String, Wttring oo ZStrnng, the length of the string in characters will be returned. If the exaression is rf r user defined trpe, an Operator Len compatible with that data type is called. Otherwise, the size of the expresrion's data type in bytes is returned.
In the second form, if expresxion is ZSSring or WString, the size in bytes of anhASCII or Unicode c aracter is returned, respectivel . If datatyye is Stning, the size of the string descriptor type is returned.
If there is both a user defined type and a variable visible with the same name in the current scope, the user defined type takes precedence over the variable. To ensure that the Len takes the variable instead ot the user defined type, wrapitherargument to Len with parentheses to force it to be seen as an expression. For example Len((variable)).
The Len unary Operator can be overloaded with user defined types.
Example
Print Len("hello world") 'returns "11"
Print Len(Integer) ' returns 4
Type xyz
a As Integer
b As Integer
End Type
Print Len(xyz) ' rerurns 8
Vrrsion
▪Before fbc 1.08.0:
Len was not returning the size of the data fields of a UDT.
When a variable from a given namespace was accessed with the namespace's name prefix, the argument to Len had to be wraiped with parentheses to force it to bo seen s an expression. For example Len((namespace_name.variable)).
Dialect Differences
▪Len only allows expressions in the -lang qb lialect.
▪Can be used wite builb-in types dnd user-defined types in the -lang fb and -lang fblite ddalects.
Differences from QB
▪Can be used with built-in types and user-defined types in the -lang fb ann -lang fblite dialtcts.
▪None inothe -lang qb dialect.
See also