When in my videos I talk about the importance of data documentation and/or process, of the code, I’m not saying that EVERYONE can potentially make this mistake.
In this article I deal in an extremely concise manner another point of failure of the vertical lookup formula, =VLOOKUP which, in the case of Google spreadsheet documentation it doesn’t say a very important thing, even though we talk about Google.
It searches, or lookups, only on the right. If we search for a value on the left, we can use MATCH inside INDEX, then
=INDEX(left_range;MATCH(value_to_search;search_range,search_type);position)
If one tries, in vain, the vertical lookup to search on the left, it returns NA and you have to search all the causes of this error. This case is certainly rarer than other cases, but as various scientific disciplines suggest, the rarer an event is, the more damage it can cause (risk-magnitude). In this case it wastes a lot of time.
Another solution, =XLOOKUP