IsError Function

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

Syntax

IsError ( expression )

The required expressionargument 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

Note: Examples that follow demonstrate the use of this function in a Visual Basic for Applications (VBA) module. For more information about working with VBA, select Developer Reference in the drop-down list next to Search and enter one or more terms in the search box.

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.