VB & VBA in a Nutshell: The Language

CBool Function

Named Arguments

No

Syntax

CBool(expression)

expression

Use: Required

Data Type: String or Numeric

Any numeric expression or a string representation of a numeric value.

Return Value

expression converted to Boolean data type (True or False).

Description

Casts expression as a Boolean data type. 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 be capable of being treated as a number. Therefore, CBool("ONE") results in a type mismatch error, yet CBool("1") converts to True.

Programming Tips and Gotchas

• You can check the validity of the expression prior to using the CBool function by using the IsNumeric 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 to True (–1). Therefore, a Boolean False can be converted back to its original value (i.e., 0), but the original value of the True expression can't be restored unless it was originally –1.

See Also

IsNumeric Function