Name
Len Function
Class
Microsoft.VisualBasic.Strings
Syntax
Len(expression
)
-
expression
(required; any) Any valid variable name or expression
Return Value
Integer
Description
Counts the number of characters within a string or the size of a given variable
Rules at a Glance
If
expression
containsNothing
, Len returns 0.For a string or String variable, Len returns the number of characters in the string.
For a nonobject and nonstructure variable, Len returns the number of bytes required to store the variable in memory.
For a variable of type Object, Len returns the length of its data subtype. If the object is uninitialized, its length is 0. However, if the object contains a strongly typed class instance, an InvalidCastException exception is thrown.
For a structure, Len returns the number of bytes required to store the structure as a file. (But see the comment in Section .)
For a strongly typed object variable, such as one defined by the
Class
...End
Class
construct, Len generates an InvalidCastException exception.If
varname
is an array, you must also specify a valid subscript. In other words, Len cannot be used to determine the total number of elements in or the total size of an array.
Programming Tips and Gotchas
Len cannot accurately report the number of bytes required to store structures that contain variable-length strings. If you need to know how many bytes of storage space will be required by a structure that includes string members, you can fix the length of the strings by using the ...
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