Why ISOMITTED does not work as expected?


Hi guys,

Take a look at the following figure, the formula in A1 is



What I expected is that A1=TRUE. Many thanks!

3 Replies
best response confirmed by Hans Vogelaar (MVP)


TRUE is returned by


@Sergei Baklan Thanks, it works. I've never heard of this syntax, could you please tell me where to find the document about it? Thanks again!


Sorry, I'm not sure about the documentation, please try to google.

Parameter(s) in bracket means optional one which could be omitted. Thus you may check for such optional parameters if they are omitted or not. And if omitted assign default value or do something you wish.

If parameter is not optional it can't be omitted and shall be passed to function. With ISOMITTED() you may check optional parameters. As an example

=LAMBDA(x, [y], LET( z, IF( ISOMITTED(y), 10, y), x+z) )(5)