Forum Discussion

Anonymous

Not applicable

5 years ago

How List.PositionOF works

But this result seems strange only to me? For the moment I do not exploit what does not fit me. I would like to see if anyone else has the same impression as me.

General Comment

Community Champion

5 years ago

Anonymous Yes, my point is since no ascii code is assigned to "", why Text.PositionOf returns positions of "" in "aba", whereas "aba" doesn't split at those positions?

Nowhere to find an explanation to the mechanism to parse "" by PQ. 🤔

Anonymous

Not applicable

5 years ago

I came up with this idea, to give a possible explanation to your interesting observation:
"" is obviously not a character but it is a text (empty but text, while the "empty" character does not exist).

If "" could be used as a character it would become a sort of wildcard like the "?".
In fact, if you use the function:
Text.EndsWith ("abc", "c")
gives TRUE
and the same happens with

Text.EndsWith ("abc", "") -> TRUE.

From this we could derive that "c" = "" 🙂 and if it holds for c, it holds for any other character.

Icey
Community Support
5 years ago
Hi Anonymous ,

Why can't we think of it this way: “abc” ends with "" when in " Text.EndsWith("abc", "") " and "abc" ends with "c" when in " Text.EndsWith("abc", "c") "?

There can be a "" behind "c" in "abc", right?🤔

Best Regards,

Icey

If this post helps, then please consider Accept it as the solution to help the other members find it more quickly.
- Anonymous
  Not applicable
  5 years ago
  
  <<If "" could be used as a character it would become a sort of wildcard like the "?".>>
  
  What was written was to prove that "" is a string and not a single character, because if it were(*) there would be the contradictory result that "" is equal to any character.
  
  However, apart from these dialectical joke, what I wanted to point out is that the
  Text.PositionOf ("abc", ...)
  finds only 3 empty substrings and not 4 as I would have expected (also for symmetry),
  
  If you use Text.PositionOf (text.reverse ("abc"), ...) you get the same result)
  
  PS
  I observed this, in my opinion strange, behavior while trying to find a custom function for the VLOOKUP
  
  (*)
  if "" is considered, as it actually should, as a string instead there is no contradiction as there is not in these cases:
  
  Text.EndsWith("abc","c")=true
  Text.EndsWith("abc","bc")=true
  from which the only logical consequence that can be drawn is that one of the two strings is a substring of the other, but not that they are equal