How to Replace Null value with previous month value

[Kumud K]

Let's see I have excel data with 3 columns I'd, date, result

If the result column for this month's date is empty then, need to update the result column with its previous month's value.

[Fabian Duerr]

Please try the LastValidBefore() function.

It substitutes null values in a column with the last valid value before the missing value.

PS: There is also a FirstValidAfter() function