IsError

Return TRUE if the expression is an error value.

Syntax
      IsError(expression)

Key
   expression    A variable.

The IsError() function can be used in VBA.

Example

Dim myvar, mycheck
myvar = someFunction()
mycheck = IsError(myvar)

“An optimist will tell you the glass is half-full; the pessimist, half-empty; and the engineer will tell you the glass is twice the size it needs to be”

Related:

Nz - Detect a NULL value or Zero Length string.