Returns a value you specify if a formula evaluates to an error; otherwise, returns the result of the formula. Use the IFERROR function to trap and handle errors in a formula (formula: A sequence of values, cell references, names, functions, or operators in a cell that together produce a new value. A formula always begins with an equal sign (=).).

'Declaration
 
Public Class CalcIfErrorFunction 
   Inherits CalcBuiltinFunction

'Usage
 
Dim instance As CalcIfErrorFunction

public class CalcIfErrorFunction : CalcBuiltinFunction