Excel has two error detection functions that are almost identical: ISERR and ISERROR. Their syntaxes are identical:
ISERR(value) and ISERROR(value). They will both return True if the value throws an error. The difference is the ISERROR function will detect #N/A errors and ISERR won’t.
Between the Sheets — Excel podcast episode 45: using the Let function
In partnership with Experts Exchange. Introduced in the 365 editions of Excel, the Let function lets you define variables, their values and calculations that use