O
PERATOR
’
S
M
ANUAL
WRXi-OM-E Rev B
191
Scripting with VBScript
S
EPARATORS
The two separators in VBS are the colon
:
and the single quotation mark .
Using the colon, you can place two or more statements on a line, for example:
XMin = 0.0
:
XMax = 800.0
:
YMin = 0.0
:
YMax = 600.0
There is also an implied separator whenever a new line is begun.
Using the quotation mark you can signify that the remainder of the line is a comment: non-executable material
that is usually used to clarify the workings of the script. For example:
RMSMax = 32767 / Sqr (2) ' RMS of the largest sinusoid that can be
' fitted into the screen in unscaled mode.
To continue a comment on to another line, another quotation mark is required on the new line.
Variable Types
VBS supports the following variable types:
Integer
signed 16 bit value in the range -32768 to 32767
Long
signed 32 bit value in the range -2
31
to +2
31
- 1
Single
real number or floating point number
Double
real number or floating point number
Boolean
Boolean or logical value
String
string of characters
When making comparisons using real numbers, beware of testing for equality, because of rounding errors. It may
be better to apply a tolerance band. For Boolean, integers and strings, equality is valid.
You can use variables in VBS without declaring the type. The context may force an implicit type assignment. For
example, if the result of a calculation is of a different type from the defined type, the type may be changed. Always
set out calculations in such a way that type changes will not affect the final result in an undesirable or
unpredictable way. If you want to change the type of a variable or a result, use a conversion function that will
show others what you intend to happen. The conversion functions are CDbl, CInt, CLng, CSng, CStr.
Variable Names
Upper and lower case have no significance in VBS, either in variable names or in keywords (the names reserved
by the system), but it is a good idea to be consistent about the spelling of a variable name to avoid confusion. At
least 36 characters may be used in a variable name. These can include any combination of alphabetic and
numeric characters, and the underscore character. No other punctuation character may be used in a variable
name.
Do not use
any of the following characters in a variable name:
! @ & $ # ? , * . { } ( ) [ ] = + - ^ % / ~ < > : ;
Just use alphanumerics and underscore, for example: Example_Name
If you have to introduce constants, give them sensible names, just like variables. For example, do not write:
_
If RMS < 23169 Then OutputY = Y
Its meaning may not be obvious to someone else.
It is better to write something like this:
FullScale = 32767
RootTwo = Sqr (2.0)
