Name
CBool Function
Syntax
CBool(expression
)
-
expression
Use: Required
Data Subtype: String or Numeric
Any numeric expression or a string representation of a numeric value.
Return Value
expression
converted to a variant with a
subtype of Boolean (True
or
False
).
Description
Casts expression
as a Variant with a
Boolean subtype. Expressions that evaluate to
are converted to False
(0), and expressions that
evaluate to nonzero values are converted to True
(-1).
Rules at a Glance
If the expression to be converted is a string, the string must act as
a number. Therefore, CBool("ONE")
results in a
type mismatch error, yet CBool("1")
converts to
True
.
Programming Tips & Gotchas
You can check the validity of the expression prior to using the
CBool
function by using theIsNumeric
function.When you convert an expression to a Boolean, an expression that evaluates to is converted to
False
(0), and any nonzero number is converted toTrue
(-1). Therefore, a BooleanFalse
can be converted back to its original value (i.e., 0), but the original value of theTrue
expression can’t be restored unless it was originally -1.
See Also
IsNumeric Function |
Get VBScript in a Nutshell now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.