Returns a Boolean value indicating whether an expression is an error value.

Syntax

IsError(expression)

The required expression argument can be any valid expression.

Remarks

Error values are created by converting real numbers to error values using the CVErr function. The IsError function is used to determine if a numeric expression represents an error. IsError returns True if the expression argument indicates an error; otherwise, it returns False.

Example

This example uses the IsError function to check if a numeric expression is an error value. The CVErr function is used to return an Error Variant from a user-defined function. Assume 

UserFunction
is a user-defined function procedure that returns an error value; for example, a return value assigned with the statement 
UserFunction = CVErr(32767)
, where 32767 is a user-defined number. 
Dim ReturnVal, MyCheck ReturnVal = UserFunction() MyCheck = IsError(ReturnVal) ' Returns True.