VBScript Reference Manual for InduSoft Web Studio

InduSoft Web Studio VBScript Reference Manual
VBScript Keywords
VBScript has many keywords. These keywords include the built-in constants and literals, operators,
functions, statements and objects. These keywords are reserved, i.e. they cannot be used as names of
variables or constants.
We have already covered the VBScript built-in implicit constants (keywords). Below are the VBScript
literal keywords, followed by operators, functions, statements and objects.
VBScript Literals
Literal keywords are used to define variables and constants, or comparison of variables.
VBScript Literal Keywords
Keyword Description
Empty Uninitialized variable value, e.g. a variable it is created but no value has been assigned to it, or
when a variable value is explicitly set to empty. Note: Empty is not the same as Null.
False Boolean condition that is not correct (false has a value of 0)
IsNothing Variable is an initialized object.
IsEmpty Variable is uninitialized.
IsNull Variable contains invalid data.
Nothing Indicates an uninitialized object value, or disassociate an object variable from an object to release
system resources.
Null Variable contains no valid data. Note: This is not the same as Empty or Nothing
True Boolean condition that is correct (true has a value of -1)
The following are example uses literal keywords
Dim valve_closed, pump_on, a
If valve_closed = True Then pump_on = False
a = Empty
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